Most grasshoppers in temperate climates first appear as tiny nymphs in mid to late spring, become increasingly visible through early summer, and reach peak numbers as adults from July through September. The exact timing depends on species, latitude, and how quickly the soil warms after winter. But the broad pattern holds across most of North America and Europe: grasshoppers are creatures of warmth, and their seasonal arc tracks the rise and fall of temperatures with surprising precision.
How the Cycle Begins Underground
The vast majority of grasshopper species spend winter as eggs buried in the soil. Females deposit clusters of eggs, called egg pods, into the top few centimeters of ground during late summer and fall. Each pod contains anywhere from a couple of dozen to over a hundred eggs, depending on the species, cemented together and insulated by a frothy secretion that hardens around them. These pods sit through months of cold, waiting for the right combination of warmth and moisture to trigger development.
Egg depth matters more than you might expect. Some species lay their egg pods very close to the surface, while others deposit them a couple of centimeters down. The white-whiskered grasshopper, for example, places its eggs at a shallow depth of roughly half a centimeter, which exposes them to colder minimum temperatures during winter than species like the migratory grasshopper that lay vertical egg pods deeper in the soil.1Journal of Orthoptera Research. Influence of cold temperature and exposure time on egg overwintering survival in the white-whiskered grasshopper (Orthoptera: Acrididae) Snow cover acts as a blanket: a few centimeters of snow can mean the difference between eggs surviving a brutal cold snap and being killed outright. In years with early snow that sticks around, overwinter survival tends to be better. In years with bare soil and deep freezes, shallow-laid eggs take the biggest hit.
Spring Hatch and the Nymph Stage
Once soil temperatures climb into a consistently warm range in spring, embryonic development resumes and nymphs begin chewing their way out of the egg pod. In the central United States, this typically starts in late April or May. In northern states and southern Canada, it may not happen until late May or June. In the southern US, hatching can begin as early as March.
The newly hatched nymphs look like miniature, wingless versions of the adults. They go through five or six molts over the course of several weeks, growing larger and developing wing pads that become functional wings only after the final molt. During this nymphal period, grasshoppers are present but easy to overlook. They are small, they blend into vegetation, and they have not yet developed the powerful flight muscles that make adults so conspicuous. If you are noticing grasshoppers jumping around your garden in late May, they have likely been there for a couple of weeks already, just too small to catch your eye.
Development speed depends heavily on temperature. Warmer springs push nymphs through their molts faster, while cool, wet springs slow everything down. A nymph that might reach adulthood in five weeks during a hot year could take seven or eight weeks during a cool one. This is why grasshopper “outbreaks” are often associated with warm, dry springs: the insects develop faster, more of them survive the nymphal stage, and they reach reproductive maturity sooner.
Peak Activity in Summer
Adult grasshoppers hit their stride from roughly late June through September, depending on species and location. This is when they are most visible, most numerous, and most damaging to crops and gardens. Adults can fly, they feed voraciously to fuel reproduction, and they are large enough to be unmistakable.
Grasshoppers are cold-blooded, so their daily routine is shaped by temperature in a very direct way. In the field, adults follow a predictable daily sequence: they bask on bare soil early in the morning to warm up, absorbing solar radiation to raise their body temperature as much as 7°C above the surrounding air temperature. As the day heats up and soil surface temperatures climb past about 35°C, the ground becomes too hot and they move up onto vegetation, where they can fine-tune their body temperature by shifting to different heights on the plant.2PubMed Central. Short-term dynamics of behavioral thermoregulation by adults of the grasshopper Melanoplus sanguinipes This climbing behavior is why you often see grasshoppers perched on the upper portions of grass stems and crop plants during midday: they are not just feeding, they are thermoregulating.
On overcast or cool days, grasshoppers are sluggish. They may barely move, spending most of the day pressed flat against sun-warmed surfaces. On hot, sunny days, they are hyperactive, flying readily, feeding aggressively, and mating. If you have ever noticed that grasshoppers seem to explode out of the grass on a hot August afternoon but are barely visible on a cool morning, that temperature-driven behavior pattern is the reason.
Late Summer Mating and Egg Laying
Mating begins shortly after adults reach their final molt and continues through late summer and into early fall. Males court females with stridulation (rubbing their hind legs against their wings to produce buzzing or clicking sounds) or with visual displays like leg-waving. After mating, females begin searching for suitable egg-laying sites, typically bare or sparsely vegetated patches of firm soil. Loose, sandy soil and heavily shaded ground are generally avoided.
A single female may lay several egg pods over the course of a few weeks, depositing them in different spots. The timing of egg laying is one of the most consequential moments in the grasshopper life cycle, because it determines where the next generation will overwinter. Females that lay early in warm soil give their embryos a head start on development before winter dormancy sets in. Females that lay late, or into cold soil, produce eggs that enter dormancy at an earlier developmental stage and may need more accumulated warmth the following spring to hatch.
By mid to late fall in most temperate areas, adult grasshoppers are dying off. The first hard frosts kill most remaining adults within days. A few stragglers may survive into November in sheltered spots, but for most species, the adult lifespan is measured in weeks to a couple of months after the final molt. By the time winter arrives in earnest, the above-ground population is gone. The species persists only as eggs underground.
Species That Break the Standard Timeline
Not every grasshopper follows the neat spring-hatch, summer-adult, fall-die pattern. A handful of North American species hatch in the fall and spend winter as partly grown nymphs rather than as eggs. These include the clear-winged grasshopper (Camnula pellucida’s relatives aside), as well as several band-winged species like Arphia conspersa, Pardalophora apiculata, Xanthippus corallipes, and Chortophaga viridifasciata.3The Canadian Entomologist. A Two-Year Life-Cycle in Grasshoppers (Orthoptera: Acrididae) Overwintering as Eggs and Nymphs These nymphs hunker down under leaf litter or in soil crevices during the coldest months, resume feeding as soon as temperatures allow in early spring, and reach adulthood weeks before the egg-overwintering species even hatch.
If you see a grasshopper hopping around on a warm day in March or early April, before it seems like any insects should be out, it is almost certainly one of these nymph-overwintering species. They tend to be among the band-winged grasshoppers, the group known for flashing colorful hind wings during flight. Chortophaga viridifasciata, often called the green-striped grasshopper, is one of the first insects active in spring across much of eastern North America, sometimes appearing on sunny hillsides when patches of snow are still visible nearby.
Some species in alpine or subarctic environments take the slow approach even further, stretching their life cycle across two full years. In these habitats, the growing season is so short that nymphs cannot complete development in a single summer. They overwinter once as eggs, hatch the following spring, feed and grow through a brief summer without reaching adulthood, overwinter again as nymphs, and finally mature the second summer. This two-year cycle is uncommon but documented in several high-altitude and high-latitude populations.
Freeze Tolerance in Cold Climates
Grasshoppers in alpine and subpolar environments face conditions that would kill most lowland species outright, yet some have evolved remarkable cold tolerance. Research on an alpine grasshopper population found that more than 70% of individuals survived single freeze events throughout the year, and repeated freeze-thaw cycles did not erode that tolerance. The grasshoppers showed seasonal fine-tuning of their freeze tolerance, adjusting their cold hardiness in step with environmental temperatures.4PubMed Central. Canalization of freeze tolerance in an alpine grasshopper
This means some alpine grasshoppers are not simply avoiding cold by going dormant. They are actively surviving being frozen. Their tissues can withstand ice formation, a physiological trick that allows them to persist at elevations and latitudes where the frost-free season is only a few months long. For these species, “coming out” in spring is less about eggs hatching and more about nymphs or even adults thawing and resuming activity once daytime temperatures climb high enough.
How Geography Shifts the Timeline
The seasonal timeline described so far is a rough average for the middle latitudes of North America. In practice, geography creates enormous variation. In the southern Great Plains, some grasshopper species are active by March and may produce two generations per year if the warm season is long enough. In the northern Great Plains and Canadian prairies, grasshoppers may not hatch until late May or early June, with adults peaking in August and dying off by late September. In tropical and subtropical regions, grasshoppers can be active year-round, with population peaks tied to rainy seasons rather than temperature.
Altitude compresses the timeline in much the same way that latitude does. A grasshopper population at 3,000 meters in the Rocky Mountains might have an active season of only three to four months, while a population of the same species at 1,500 meters a few hundred kilometers away enjoys five or six months of warmth. The higher population hatches later, grows more slowly, and must complete its life cycle in a tighter window.
Modeling work on alpine grasshopper species in the Southern Hemisphere has highlighted just how sensitive these compressed-season populations are to even small temperature shifts. Under a scenario of roughly 1°C of warming, several alpine species were projected to lose more than half of their predicted suitable habitat, with one species facing a loss of 95% of its range.5PubMed Central. Climate change and alpine-adapted insects: modelling environmental envelopes of a grasshopper radiation The issue is not that warmth is inherently bad for grasshoppers; it is that alpine-adapted species are specialized for narrow temperature bands, and warming pushes those bands uphill until there is no more mountain left.
Climate Change Is Rewriting the Calendar
For grasshoppers at lower elevations and across the broad grasslands of North America, the story of climate change is different: warming tends to expand their active season and push their ranges northward. Research modeling the effects of climate change on six co-occurring North American grasshopper species found that early-season species, including several of the nymph-overwintering band-wings, showed northern range expansions under warming scenarios. For Arphia conspersa, the northern range limit in March shifted from Iowa and Nebraska to North Dakota and Montana under moderate warming projections.6PubMed Central. Phenology dictates the impact of climate change on geographic distributions of six co‐occurring North American grasshoppers In practical terms, this means grasshoppers are appearing earlier in the year and farther north than they used to.
But earlier emergence does not just affect the grasshoppers themselves. It can ripple through the food web. A decade-long study in Inner Mongolia found that warming April temperatures created a growing mismatch between the timing of lark hatching and the availability of grasshopper nymphs, the birds’ main food source. When grasshoppers emerged earlier but the birds’ breeding schedule did not shift to match, the resulting timing gap affected grassland productivity through cascading ecological effects.7PubMed. Phenological mismatches between larks and grasshoppers induced by climate change degrade a grassland ecosystem through trophic cascades Grasshopper timing, in other words, is not just a question for entomologists or farmers. It structures entire grassland ecosystems.
What This Means for Your Yard and Garden
If you are trying to figure out when grasshoppers will show up in your specific area, the most reliable cue is soil temperature. Once the top few centimeters of soil are consistently warm in spring, eggs start hatching. In most of the US, that means you should expect the first tiny nymphs sometime between late April and early June. They will be easy to miss at first, since newly hatched nymphs are only a few millimeters long and tend to stay low in the grass.
By midsummer, the population is in full swing. If you are a gardener dealing with grasshopper damage, the window for the most effective intervention is early, during the nymph stage, before the insects develop wings and become harder to manage. Once adults are flying freely in July and August, controlling them becomes much more difficult. Any bait or barrier strategies work best when the grasshoppers are still small, flightless, and concentrated near their hatch sites.
The decline is just as predictable as the rise. Watch for the first sustained frost in your area; within a week or two of that, most adult grasshoppers will be gone. A few hardy individuals may linger into late fall on south-facing slopes or near warm structures, but the population crash after the first freeze is dramatic. By the time you are raking leaves, the grasshoppers have already laid their eggs and checked out for the year.
Why Some Years Are Worse Than Others
Grasshopper populations are famously boom-and-bust. You might barely notice them for a few years running, then suddenly they seem to be everywhere. The main drivers are weather patterns across two consecutive years: the year the eggs were laid and the year they hatch. A warm, dry late summer encourages heavy egg laying and good egg-pod survival. A warm, dry spring the following year accelerates hatching and nymphal development while reducing the fungal diseases and parasites that kill nymphs during cool, wet conditions. Stack two favorable years back to back and you get an outbreak.
Conversely, a cold, wet spring can collapse a population. Nymphs develop slowly, fungal pathogens thrive in damp conditions, and cool temperatures leave the insects too sluggish to feed and grow efficiently. If you have had a couple of wet springs in a row, grasshopper numbers tend to be low even if the summers themselves are hot.
Natural enemies also play a role. Blister beetle larvae feed on grasshopper egg pods in the soil. Parasitic flies and wasps attack nymphs and adults. Birds, from larks to kestrels, consume enormous quantities during the summer months. In a healthy grassland ecosystem, these predators and parasites keep grasshopper numbers from exploding every year. Outbreaks tend to happen when weather conditions overwhelm those natural checks, producing such a large cohort of nymphs that predators cannot keep up.
Grasshoppers vs. Crickets and Katydids
People sometimes confuse grasshoppers with their close relatives, and the confusion matters because their seasonal timelines differ. Crickets, particularly field crickets, often overwinter as nymphs rather than eggs, which means they can be active earlier in spring than most grasshoppers. Katydids, on the other hand, tend to be late-season insects: many species do not reach adulthood until July or August and are most conspicuous in the fall, when their calls dominate the nighttime soundscape. Grasshoppers sit in the middle, with their peak firmly in midsummer.
The easiest way to tell them apart seasonally: if you are hearing loud insect calls on warm evenings in September and October, those are almost certainly crickets or katydids, not grasshoppers. Grasshoppers do stridulate, but their sounds are quieter and produced during the day. The loud, pulsing chorus of late summer nights belongs to their nocturnal cousins.