Termite Swarm Season in Hawaii: 2026 Timing & Risk
3 species, peak swarms May 1 – June 30, infestation probability zone I (very heavy) — plus whether today is swarm weather in Honolulu, Hilo, Waimea (Kamuela).
Next swarm window opens February 1 (Asian subterranean) · 115 daysThe Hawaii termite year at a glance
Typical window, checked against today's dateThe University of Hawaii estimates Formosan termites cost the state more than $100 million a year — Hawaii is the only state where termite pressure is essentially year-round.
Is today swarm weather in Hawaii?
Subterranean termites launch on the first warm (70°F+), humid, calm days after a soaking rain inside their window; drywood and dampwood species fly on warm, still late-summer evenings. The rows below read today's high, humidity, the last 48 hours of rain, and wind for Hawaii's three reference cities and score them against the species windows that are open right now (none open today, so the score is capped).
| City | High today | Humidity | Rain, last 48 h | Wind | Swarm conditions |
|---|---|---|---|---|---|
| Honolulu | … | … | … | … | Loading |
| Hilo | … | … | … | … | Loading |
| Waimea (Kamuela) | … | … | … | … | Loading |
Score 0–10: Unlikely 0–2.9 · Possible 3–5.4 · Likely 5.5–7.4 · Swarm conditions 7.5+. Weather from api.open-meteo.com, read in your browser when the page loads. A high score means conditions favor a flight somewhere nearby — not that your house is infested.
Which termites swarm in Hawaii, and when
Formosan subterranean termite
Coptotermes formosanus- Swarms in Hawaii
- April 1 – July 31, evening
- Local notes
- The Formosan subterranean termite is Hawaii's most destructive pest; evening flights peak May–June on Oahu, with smaller flights year-round.
- Damage pattern
- Colonies of several million that can hollow a joist in months; builds above-ground carton nests in walls.
Drywood termite
Incisitermes and Cryptotermes species- Swarms in Hawaii
- May 1 – September 30, night
- Local notes
- West Indian drywood termites in furniture, rafters, and door frames on every island; night flights in summer.
- Damage pattern
- Lives entirely inside dry wood — attics, furniture, trim — no soil contact; leaves six-sided fecal pellets.
Asian subterranean termite
Coptotermes gestroi- Swarms in Hawaii
- February 1 – May 31, night
- Local notes
- Asian subterranean termites established on Oahu and spreading; night swarms late winter–spring.
- Damage pattern
- As aggressive as Formosan; hybridizes with it in Florida.
Hawaii is in termite infestation probability zone I
The International Residential Code's Termite Infestation Probability Map (built on US Forest Service survey data) divides the country into four bands. Local jurisdictions use it as the basis for the termite-protection requirements they write into the code; homeowners can use it to set expectations. The figure names those bands rather than numbering them — the zone I–IV shorthand here is ours, not the code's, and the figure warns its lines are approximate. Hawaii: zone I, very heavy. The Gulf and Deep South — Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina, and eastern and coastal Texas — plus nearly all of California. The band's northern edge runs near the North Carolina line, and we place North Carolina here on the strength of its coastal plain. (We place Hawaii here too; the code figure maps only the lower 48.) Termites reach most structures eventually, and in this band the code also bars below-grade foam plastic on foundation walls and slabs.
Very heavy
The Gulf and Deep South — Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina, and eastern and coastal Texas — plus nearly all of California. The band's northern edge runs near the North Carolina line, and we place North Carolina here on the strength of its coastal plain. (We place Hawaii here too; the code figure maps only the lower 48.) Termites reach most structures eventually, and in this band the code also bars below-grade foam plastic on foundation walls and slabs.
Moderate to heavy
The mid-South, the Mid-Atlantic, the lower Midwest, and the interior and desert Southwest — Arizona, Nevada, and New Mexico included. Infestations are common; routine inspection is the norm in home sales. In the low-desert metros the local pressure runs well above what this band suggests.
Slight to moderate
The northern tier, the Rockies, and the Pacific Northwest. Colonies are localized; carpenter ants cause more wood damage than termites do.
Bands are assigned to each state's populated core; several states straddle a boundary (the state note above says which parts). No public-domain copy of the IRC map is available, so the zones are listed rather than drawn.
Hawaii termite hotspots
Honolulu and urban Oahu
Formosan colonies in nearly every older neighborhood; the species arrived here before the mainland.
Hilo
The wettest city in the US and constant drywood and Formosan activity.
Kahului–Wailuku, Maui
Warm, humid lowlands with plantation-era wood housing.
Signs of termites in Hawaii homes
Swarmers vs. flying ants
Termites: straight antennae, thick waist, four equal wings twice the body length. Ants: elbowed antennae, pinched waist, front wings longer than hind. Save a few in a bag — identification decides everything that follows.
Discarded wings
Swarmers shed their wings minutes after landing. Piles of identical translucent wings on a windowsill, in a spider web, or on a tub floor are the most common first sign — often with no insects left in sight.
Mud tubes
Pencil-width earthen tunnels climbing a foundation wall, pier, or plumbing penetration. Subterranean termites build them to stay moist between soil and wood. Break one open — live workers inside mean an active colony.
Frass (drywood pellets)
Drywood termites push six-sided, sand-like pellets out of kick-out holes — tiny piles under a window frame, rafter, or furniture. Drywood termites are established in Hawaii, so this is a sign to take seriously here.
Hollow or blistered wood
Baseboards that sound papery when tapped, paint that bubbles like water damage, doors that suddenly stick. Subterranean galleries run with the grain and are packed with mud; drywood galleries are clean and cross the grain.
Moisture clues
Termites follow water. A leaking hose bib, a downspout dumping at the foundation, mulch piled against siding, or a damp crawlspace is where inspectors look first.
What to do when you see a swarm in Hawaii
Preventing termites in Hawaii
Prevention is mostly moisture and wood-to-soil management, and most of it costs a weekend rather than a contract. In a zone I state, these are the habits that keep a home off the treatment list:
- Keep 6 inches of visible foundation between soil or mulch and any siding, trim, or sill plate. Mulch piled to the siding is the most common entry invitation inspectors find.
- Move water away. Downspout extensions, grading that slopes away from the house, and a crawlspace vapor barrier remove the moisture subterranean colonies need.
- Break wood-to-soil contact. Deck posts on metal standoffs, no firewood or lumber stacked against the house, stumps removed, and fence posts that don't touch the foundation.
- Seal slab and foundation penetrations where plumbing and conduit enter — termites need a crack the width of a business card.
- Fix leaks fast. A dripping hose bib or AC condensate line against the foundation creates a permanent wet spot that colonies home in on.
- Screen attic and crawlspace vents with fine mesh and seal cracks in exposed rafter tails and fascia — drywood swarmers enter through the smallest openings in exposed wood.
- Watch the trees. Formosan colonies nest in live oaks, pecans, and other yard trees and reach the house from above ground — a carton nest in a tree within 100 feet of the home is a treat-now signal.
- Inspect annually — a $75–$150 professional inspection (or a thorough flashlight walk of the crawlspace and foundation each spring) catches mud tubes years before structural damage.
Hawaii termite swarm FAQ
More Hawaii pest timing
More West termite swarm seasons
Swarm windows are climatological typicals compiled from land-grant extension guidance (UF/IFAS, LSU AgCenter, Texas A&M, UC IPM, and state extension services) and from the IRC Termite Infestation Probability map; any single year runs 1–3 weeks either side. Cost ranges are general industry figures, not quotes. Live conditions from Open-Meteo. Hawaii extension guidance: www.ctahr.hawaii.edu/termite/. National picture: where termites are swarming right now →
Hero image: “Formosan termite alates” — USDA Agricultural Research Service (Scott Bauer) — Public domain