Seasonal & Climate Patterns for Termite Activity

What is Swarming?

Swarming is the mass emergence of winged reproductives (alates) from a mature colony. These termites fly to find mates and establish new colonies. Swarming is often the first visible sign of an established infestation.

Why it matters:

• Indicates a mature, established colony nearby
• Visible sign that's easy to spot
• Triggers for professional inspection
• Timing varies by species and climate

Spring Swarming (March-May)

Peak activity: Most common swarming season across the U.S.

Triggers:

• Warming temperatures (typically 60-70°F+)
• After rain or high humidity
• Morning hours, especially after sunrise
• Near light sources (windows, porch lights)

What to look for:

• Discarded wings near windows or doors
• Live winged termites indoors or on exterior
• Swarms near foundation or wood structures
• Activity lasting 30 minutes to several hours

Action: Spring is ideal inspection time. If you see swarmers, schedule professional inspection immediately.

Fall Swarming (August-October)

Peak activity: Secondary swarming season, less predictable than spring.

Triggers:

• Cooling temperatures after summer heat
• Increased humidity and rainfall
• Evening hours (less common than spring)
• Species-dependent (Formosan termites more active in fall)

What to look for:

• Discarded wings (may be more scattered)
• Swarmers near lights
• Activity in walls or attics
• Less predictable timing than spring

Action: Fall is good time for preventive inspections before winter.

Warm Climates (South, Southwest, Coastal)

Subterranean termites: Active year-round

• No winter dormancy period
• Continuous foraging and damage
• Multiple swarming periods possible
• Highest risk for severe infestations

Drywood termites: Active year-round

• Swarming typically May-September
• Peak activity in summer
• Damage accumulates continuously

Inspection recommendation: Year-round vigilance. Inspect quarterly or semi-annually.

Temperate Climates (Mid-Atlantic, Midwest)

Subterranean termites: Active spring through fall

• Winter dormancy (November-February)
• Spring emergence (March-May)
• Summer foraging (June-August)
• Fall activity before dormancy (September-October)

Drywood termites: Less common, limited activity

• Swarming typically June-August
• Winter survival limited
• Primarily in heated structures

Inspection recommendation: Spring and fall inspections critical. Summer for active monitoring.

Cold Climates (Northeast, Upper Midwest, Mountain)

Subterranean termites: Active May-September

• Long winter dormancy (October-April)
• Short active season
• Rapid spring emergence
• Fall preparation for dormancy

Drywood termites: Rare in unheated structures

• Only in heated homes or buildings
• Limited regional presence

Inspection recommendation: Late spring (May) and early fall (September) inspections. Winter dormancy reduces but doesn't eliminate risk.

January-February (Winter)

Activity level: Low (cold climates), Moderate (temperate), High (warm climates)

• Subterranean termites dormant in cold regions
• Interior inspection recommended (warm climates)
• Plan spring professional inspection

March-May (Spring)

Activity level: Very High (peak swarming)

• Primary swarming season across all regions
• Ideal time for professional inspection
• Watch for discarded wings
• Schedule treatment if needed

June-August (Summer)

Activity level: High (continued foraging)

• Swarming less common but possible
• Active foraging and damage
• Moisture issues peak (humidity)
• Good time for preventive measures

September-November (Fall)

Activity level: Moderate to High

• Secondary swarming possible
• Termites preparing for dormancy (cold climates)
• Good time for follow-up inspection
• Prepare home for winter

Temperature

Optimal range: 75-85°F for most termite species

• Below 50°F: Most activity stops (except in heated structures)
• 50-70°F: Reduced activity, swarming may occur
• 70-85°F: Peak activity and foraging
• Above 85°F: Activity continues but may slow in extreme heat

Humidity

Critical factor: Termites dehydrate quickly and need moisture

• High humidity (60%+): Ideal conditions, increased activity
• After rain: Swarming often triggered
• Wet soil: Easier mud tube construction
• Dry conditions: Activity decreases, termites retreat to soil

Rainfall

Triggers swarming: Rain followed by warm weather

• Increases soil moisture
• Triggers reproductive emergence
• Creates ideal conditions for new colony establishment
• Spring rains particularly significant

Highest Risk Regions

• Gulf Coast: Year-round activity, multiple species, severe damage potential
• Southeast: High humidity, warm temperatures, Formosan termites
• Southwest: Drywood termites, dry climate but active year-round
• California: Drywood and subterranean, coastal humidity

Moderate Risk Regions

• Mid-Atlantic: Seasonal activity, spring/fall peaks
• Midwest: Seasonal dormancy, spring emergence
• Upper South: Extended warm season, moderate year-round risk

Lower Risk Regions

• Northeast: Short active season, winter dormancy
• Upper Midwest: Limited active season, cold winters
• Mountain West: Elevation and cold limit activity