Termites are most active in spring — typically March through May in most of the United States — when warming temperatures and rain trigger reproductive swarms. According to Texas A&M AgriLife Extension, Reticulitermes species (the most common subterranean termites in the U.S.) swarm primarily between February and May in Texas, with activity peaking after rain events when soil temperatures rise above 70°F. That visible swarm is the most recognizable sign — but it is not the only window of danger.
The word "active" covers two distinct behaviors that most people conflate. Swarming — when winged reproductives (alates) emerge to found new colonies — is seasonal and conspicuous. Feeding, by contrast, happens 365 days a year inside walls, slab joints, and soil. Colonies do not hibernate. They move deeper into soil during cold snaps to stay within comfortable thermal range, a behavior called colony thermoregulation, and return to structural wood as temperatures rise.
This is the most important misconception to correct: termites are not dormant in winter. The EPA confirms that subterranean termites remain active year-round inside heated structures, regardless of outdoor temperature. A colony established under a climate-controlled slab in December is feeding in January.
Species also changes the answer. Subterranean species peak in spring. Drywood termites (Incisitermes minor) swarm later — late summer into early fall — and their activity calendar is driven by humidity, not rainfall. If you live in a warm climate like central or south Texas, your risk window is effectively year-round, with two distinct swarm peaks depending on which species is present.
If you are reading this in swarm season, that is your signal to inspect now — not after the swarmers disappear.
Why Spring Triggers the Most Visible Activity
Termite swarms are triggered by a combination of temperature and rainfall, not by the calendar date. University of Florida IFAS Extension research documents that Reticulitermes flavipes swarms are most reliably initiated by temperatures above 70°F combined with rain events that saturate the soil — conditions that concentrate in March through May across most of the South and Southeast. Pest management professionals track this using degree-day accumulation models, the same framework used for agricultural pest forecasting.
Once swarm conditions are met, alates — the winged reproductives — exit the colony in large numbers, often through mud tubes or cracks in slabs. They are poor fliers, shed their wings within minutes, and die if they do not find a mate and suitable moist soil. What looks like a dramatic event is actually a brief, high-stakes dispersal. The swarmers you see are not the threat; the colonies they came from are.
Do Termites Really Stay Active in Winter?
Yes — feeding activity continues through winter, even when swarms stop. The NPMA and EPA both confirm that subterranean colonies maintain foraging behavior by migrating deeper into soil, where ground temperature remains stable even when surface temperatures drop below freezing. In Texas winters, where overnight lows rarely sustain below 30°F for extended periods, Reticulitermes colonies may never fully retreat from structural wood at all.
Drywood termites, which live entirely within the wood they consume rather than foraging from soil, are unaffected by soil temperature entirely. Their winter activity is functionally identical to their summer activity — quiet, concealed, and producing frass (the powdery excrement they push from small kick-out holes) at a steady rate.
Winter is not a safe season. It is simply a quieter one.
Subterranean vs. Drywood: Different Seasons, Different Signals
The species present determines when activity peaks and what evidence you will find. Subterranean termites build mud tubes — narrow, earthen channels along foundation walls, pipes, and wood framing — and swarm in spring. Drywood termites leave no mud tubes; their primary sign is frass accumulating in small piles beneath kick-out holes. Texas A&M AgriLife Extension documents Formosan subterranean termites (Coptotermes formosanus), one of the most destructive species in the Gulf Coast region, swarming from April through July — later than native subterranean species and in far greater numbers per colony.
Misidentifying species leads to the wrong treatment timing and the wrong treatment method. A liquid termiticide barrier addresses subterranean foraging; it does nothing for a drywood colony established inside a roof beam.
If you have noticed mud tubes, contact with soil at any wood joint, or piles of what looks like fine sawdust near baseboards, the species identification matters before any treatment decision is made.
Are Termites Worse After Rain?
Rain accelerates swarm events and expands subterranean foraging range. Saturated soil allows Reticulitermes colonies to extend mud tubes further from the central colony, reaching new wood sources they could not access in dry conditions. Post-rain swarms are common because the combination of warmth and moisture simultaneously meets swarming thresholds — the degree-day accumulation trigger — for large portions of a colony's reproductives at once.
In practical terms: if you see flying insects indoors within 24-48 hours after a spring rain, and they have straight antennae, equal-length wings, and a thick waist (unlike flying ants, which have bent antennae and a pinched waist), you are likely looking at termite alates. Check door frames, window sills, and any light fixtures they may have been drawn to.
For questions about what other pests may be active after rain — including how to know if you have bed bugs during a home walkthrough — a full interior inspection covers both.
What Time of Day Are Termites Most Active?
Subterranean termites forage continuously, 24 hours a day, but swarms typically occur in daylight. Reticulitermes swarms most often in morning to early afternoon hours, particularly on warm, calm days following rain. Formosan termite swarms, by contrast, are most dramatic at dusk and are heavily attracted to artificial light — a behavior that distinguishes them in the field.
Inside walls and soil, foraging has no day-night cycle. Colonies operate on task-based activity regulated by pheromones, not light. The 3 a.m. termite is as active as the noon termite.
A Month-by-Month Risk Guide for Texas Homeowners
This calendar reflects Texas conditions specifically, where mild winters compress the "low-risk" window to almost nothing:
| Month | Risk Level | Primary Activity |
|---|---|---|
| January–February | Moderate | Deep soil foraging; Formosan colonies active indoors |
| March–April | High | Reticulitermes swarm season begins; post-rain swarm events |
| May–June | High | Formosan swarm peak; colony expansion |
| July–August | Moderate–High | Drywood termite swarm season; heat drives colonies deeper |
| September–October | Moderate | Drywood secondary swarms; subterranean foraging slows |
| November–December | Moderate | Colonies shift depth; feeding continues in heated structures |
No month in Texas registers zero termite risk. That is not alarmism — it reflects the NPMA's documentation of approximately $5 billion in annual U.S. termite damage, with warm-climate states accounting for a disproportionate share.
Understanding pest control cost before a problem escalates can help homeowners budget for routine inspection. Reviewing what an exterminator near me typically charges in the Austin area is a useful starting point for annual planning.
When Professional Help Becomes Necessary
Termite activity has a defined threshold at which self-monitoring becomes inadequate. Check your situation against each of the following:
- You have observed winged insects indoors, particularly near windows, light fixtures, or door frames, within 48 hours of a rain event
- You have found discarded wings — paired, equal-length — along window sills or interior baseboards
- Mud tubes are visible on foundation walls, piers, interior walls, or plumbing penetrations
- Wood in your home sounds hollow when tapped, or shows surface blistering with no water source nearby
- You have found frass — small, pellet-like or powdery excrement — accumulating beneath baseboards or window frames
- A prior termite treatment is more than five years old, or you have no record of treatment on a home built before 2000
If two or more of these apply, a professional inspection with a written report is the appropriate next step — not a consumer bait station, which addresses foraging pressure but cannot assess colony size, species, or structural damage already done.
Homeowners in the Hill Country and surrounding communities can contact dripping springs termite control for a licensed inspection. Homeowners north of Austin can reach georgetown termite control for service in Williamson County.
For context on what treatment typically costs relative to an inspection, the breakdown of rodent control service and general pest treatment pricing in Texas reflects the broader landscape of professional pest management costs in the state.
FAQ
Q: How long does termite season last? A: Swarm season for subterranean termites typically spans 6-10 weeks in spring, concentrated from March through May in most of the South. However, "termite season" as a feeding risk is year-round — colonies do not stop consuming wood when swarms end. In Texas, Formosan termite swarms extend the visible swarm window into July.
Q: What triggers a termite swarm? A: Swarms are triggered when soil temperature exceeds approximately 70°F and a significant rain event saturates the ground — conditions that coincide in spring across most warm-climate states. University of Florida IFAS Extension documents this as a degree-day accumulation threshold that reproductive alates respond to with mass emergence. Colonies typically swarm once per year per triggering event.
Q: Are termites worse after rain? A: Yes. Rain simultaneously triggers swarm events and expands subterranean foraging range by saturating soil enough for mud tube construction to extend further from the colony. Post-rain is the highest-probability window for spotting alates indoors.
Q: What is the difference between flying ants and termite swarmers? A: Termite alates have straight antennae, a thick uniform waist, and two pairs of equal-length wings. Flying ants have elbowed antennae, a pinched waist, and front wings noticeably larger than rear wings. Both swarm in spring, but termite alates shed their wings within minutes of landing; finding equal-length, paired wings near a window sill is a reliable distinguishing sign.
Q: How often should I get a termite inspection? A: The EPA recommends annual termite inspections for homes in high-risk areas, regardless of season or whether prior treatment has been applied. Homes with prior subterranean termite history, slab-on-grade construction, or wood-to-soil contact at any point should not extend inspection intervals beyond 12 months.
Quick Reference: Termite Activity by Season
- Termites are most visibly active in spring (March–May), when warm temperatures above 70°F and rain events trigger reproductive swarms in subterranean species.
- Swarm season and feeding season are not the same thing — colonies feed continuously year-round, including through winter, by migrating deeper into soil to maintain thermal stability.
- In Texas, Reticulitermes species swarm February–May; Formosan termites (Coptotermes formosanus) peak April–July, in far larger swarm numbers.
- Drywood termites (Incisitermes minor) follow a separate calendar, swarming late summer into fall, and produce no mud tubes — only frass at kick-out holes.
- Termites cause an estimated $5 billion in property damage annually in the U.S. (NPMA), with warm-climate states contributing disproportionately due to longer active seasons.
- Rain accelerates both swarm events and subterranean foraging range, making the 48-hour post-rain window the highest-probability period for spotting alates indoors.
- Professional inspection is recommended when mud tubes, discarded wings, hollow-sounding wood, or frass accumulation are present — or when prior treatment exceeds five years.