Seattle’s unique climate creates distinct ant activity patterns throughout the year. Unlike regions with simple “summer ant season,” the Pacific Northwest experiences multiple ant emergence periods tied to our temperature, rainfall, and humidity cycles. Understanding these patterns is key to effective prevention and treatment.
The Seattle Ant Season Calendar: What Happens When
January-February: Dormant Period (But Not Always)
Typical Activity: Minimal outdoor activity
Exceptions: Indoor infestations continue, especially in heated spaces
Primary Species: Odorous house ants (year round indoors)
Weather Influence: Mild El Niño winters lead to earlier activity
Homeowner Action:
- Check for indoor activity around pipes and appliances
- Inspect crawl spaces for moisture ants
- Professional Service: Best time for preventive barrier treatments before spring emergence
March-April: Early Spring Scouting
First Outdoor Activity: Soil temperatures reach 50°F
Scout Ants Appear: Individual foragers exploring for food
Primary Locations: Kitchens, bathrooms, south facing walls
Key Indicator: First ant inside lead to colony nearby
Seattle Specific Patterns:
- Ballard/Fremont: Earlier emergence due to urban heat island
- Eastside: Slightly later (cooler microclimates)
- Waterfront Properties: Higher moisture ant activity
Critical Mistake: Ignoring “just a few scouts” lead to major infestation by June
May-June: Primary Swarm Season
Peak Activity Period: Soil temperatures 55-65°F
Swarming Events: Reproductive flights (winged ants)
Most Active Species: Carpenter ants, moisture ants
Seattle Swarm Triggers: 2 days of sunshine after rain
2024 Seattle Swarm Predictions (Based on Weather Patterns):
- Early May: First major carpenter ant swarms
- Late May: Moisture ant reproductive flights
- Early June: Pavement ant colony expansion
- Late June: Odorous house ant population peaks
Emergency Alert: Swarm indoors leads to established colony inside structure
July-August: Summer Expansion
Colony Growth Peak: Maximum worker population
Foraging Range: Expands up to 100 feet from nest
Food Sources: Natural (aphid honeydew) human
Drought Impact: Ants seek water indoors
Seattle Summer Patterns:
- Dry Summer: Increased indoor water-seeking
- Wet Summer: Continued outdoor expansion
- Heat Waves: Night foraging increases
September-October: Late Season Preparation
Final Swarms: Second carpenter ant reproductive period
Colony Preparation: Gathering resources for winter
Nest Movement: Some species move indoors
Most Problematic: New satellite colonies established
Fall Transition Issues:
- Landscaping changes disturb colonies
- First rains drive ants indoors
- Heating systems activate indoor nests
November-December: Overwintering Period
Outdoor Activity: Minimal (temperatures below 50°F)
Indoor Infestations: Become apparent as heat turns on
Crawl Space Colonies: Remain active (stable temperatures)
Holiday Season Alert: Increased food preparation = increased ant discoveries
Species Specific Seattle Timelines
Carpenter Ants (Structural Risk)
- Scouts Appear: March 15 April 15
- Swarm Season 1: May 1 June 15
- Peak Activity: June 15 August 31
- Swarm Season 2: September 1 October 15
- Overwintering: Indoors/crawl spaces
Damage Timeline: Untreated colony can cause structural concerns within 12-18 months
Odorous House Ants (Most Common Nuisance)
- Indoor Activity: Year-round
- Outdoor Emergence: April 1
- Population Peak: June 15-July 31
- Colony Splits: August-September
- Winter: Indoor nests expand
Seattle Fact: 85% of kitchen ant complaints involve odorous house ants
Pavement Ants (Foundation Concerns)
- Emergence: April 15
- Mating Flights: June
- Colony Expansion: July-August
- Preparation: September
- Overwinter: Under sidewalks, foundations
Moisture Ants (Water Damage Indicators)
- Early Activity: February-March (damp areas)
- Swarming: May-June after rains
- Peak: July-September
- Decline: October
Key Indicator: Moisture ants lead to existing water damage
Seattle Microclimate Variations
Urban Core (Downtown, Capitol Hill, SLU)
- Earlier Starts: 2-3 weeks earlier than suburbs
- Heat Island Effect: Extended activity season
- Multi Unit Spread: Rapid infestation transfer
- Primary Species: Odorous house, pavement ants
North Seattle (Ballard, Green Lake, Wallingford)
- Older Homes: More carpenter ant issues
- Mature Trees: Natural habitat connection
- Crawl Space Homes: 80% have crawl spaces
- Primary Species: Carpenter, moisture ants
Eastside (Bellevue, Kirkland, Redmond)
- Newer Construction: Different entry points
- Landscaped Yards: Bridge to structures
- Irrigation Systems: Moisture sources
- Primary Species: Odorous house, pavement ants
Waterfront Properties
- Year-Round Moisture: Higher moisture ant activity
- Driftwood/Beach Access: Natural harborage
- Primary Species: Moisture, carpenter ants
Seasonal Prevention Checklist
Spring (March-May)
- Seal exterior cracks and gaps
- Trim vegetation away from structure
- Clean gutters and downspouts
- Apply preventive barrier treatment
- Store firewood away from house
- Fix irrigation system leaks
Summer (June-August)
- Monitor for scout ants weekly
- Keep kitchen meticulously clean
- Use dehumidifiers in basements
- Check for moisture accumulation
- Inspect foundation regularly
- Maintain landscape barriers
Fall (September-November)
- Seal potential indoor entry points
- Store fall harvest properly
- Address moisture issues before rains
- Consider fall preventive treatment
- Prepare crawl space for wet season
- Clean outdoor eating areas
Winter (December-February)
- Check indoor pipes for leaks
- Monitor crawl space humidity
- Inspect attic for activity
- Plan spring treatment schedule
- Review prevention effectiveness
- Schedule professional assessment
When to Schedule Professional Treatments
Optimal Preventive Timing:
- Barrier Treatments: March 1 April 15 (before scout emergence)
- Carpenter Ant Prevention: April 1 May 1 (pre-swarm)
- Moisture Control: February (before spring rains)
- Crawl Space Treatment: Anytime, but ideal in dry periods
Reactive Treatment Windows:
- Early Infestation: Within 7 days of first sighting
- Active Swarm: Same day emergency service
- Established Infestation: Anytime, but faster leads less damage
- Seasonal Peak: Expect 3-5 day scheduling delay
2024 Recommended Schedule:
- March 15: Preventive barrier application
- May 1: Carpenter ant assessment
- July 15: Mid-season check
- September 15: Fall prevention treatment
- November 1: Pre winter inspection
Climate Change Impact on Seattle Ant Seasons
Observed Changes (2005-2024):
- Season Extension: 3-4 weeks longer active period
- Earlier Emergence: 2-3 weeks earlier than 20 years ago
- More Swarms: Increased reproductive events
- Winter Activity: More indoor infestations during mild winters
Future Projections:
- By 2030: Year round outdoor activity in urban areas
- Increased Species: Southern species migrating north
- More Damage: Extended carpenter ant feeding seasons
Adaptation Strategy: More frequent preventive treatments and monitoring
Seattle Neighborhood Specific Alerts
Ballard/Phinney Ridge:
High Risk Period: May 15 June 30
Primary Concern: Carpenter ants in older homes
Recommended Action: Pre swarm inspection April 15
Queen Anne/Magnolia:
High Risk Period: June 1 July 15
Primary Concern: Moisture ants in view properties
Recommended Action: Moisture assessment before May 1
Capitol Hill/First Hill:
High Risk Period: Year-round indoor
Primary Concern: Odorous house ants in multi-unit buildings
Recommended Action: Quarterly maintenance plans
Bellevue/Medina:
High Risk Period: April 15 May 30
Primary Concern: Pavement ants in new construction
Recommended Action: Foundation treatment in early April
Seasonal DIY vs. Professional Guide
Spring (DIY Appropriate):
- Seal cracks
- Clean gutters
- Trim vegetation
- Call Professional For: Preventive barrier treatments
Summer (Limited DIY):
- Sanitation
- Monitoring
- Call Professional For: Any active infestation
Fall (Professional Recommended):
- DIY: Cleanup, exclusion
- Professional: Treatment of established colonies before winter
Winter (Professional Only):
- Indoor infestations require professional treatment
- Crawl space assessments
- Moisture control implementation
Professional Seasonal Services
Spring Startup Package ($199)
- Exterior barrier treatment
- Carpenter ant assessment
- Moisture evaluation
- 60 day preventive warranty
Summer Maintenance ($149)
- Mid season barrier refresh
- Activity assessment
- Bait system monitoring
- Swarm response priority
Fall Prevention Treatment ($179)
- Complete exterior treatment
- Indoor entry point sealing
- Crawl space assessment
- Winter preparation guide
Year-Round Protection ($99/quarter)
- Quarterly treatments
- Priority service
- Comprehensive coverage
- Most Popular Option: Learn about maintenance plans
Emergency Seasonal Situations
Spring Emergencies (March-May):
- Cause: Scout discovery reveals established colony
- Response: Same day assessment
- Treatment: Immediate colony targeting
Summer Emergencies (June-August):
- Cause: Swarm indoors
- Response: 2-4 hour emergency service
- Treatment: Swarm control plus colony elimination
Fall Emergencies (September-November):
- Cause: First rains drive massive numbers indoors
- Response: Next day service
- Treatment: Exclusion plus population reduction
Winter Emergencies (December-February):
- Cause: Heat activation reveals indoor colony
- Response: 24/7 emergency service
- Treatment: Indoor safe methods
2024 Seattle Ant Season Forecast
Based on NOAA Predictions and 15 Year Data:
Early Spring (Above Average Risk):
- Mild winter higher survival rates
- Early emergence expected (March 10-20)
- Recommendation: Schedule preventive treatment by March 15
Swarm Season (High Risk):
- Normal rainfall optimal swarming conditions
- Peak swarming: May 20-June 10
- Recommendation: Carpenter ant inspections by May 1
Summer Activity (Extended Season):
- Warmer than average summer predicted
- Activity through September
- Recommendation: Mid August barrier refresh
Fall Transition (Moderate Risk):
- Normal rainfall patterns
- Secondary swarming likely
- Recommendation: September preventive treatment
Tracking Your Property’s Ant Patterns
Create a Seasonal Log:
- Date of First Sighting: Each year
- Locations: Where ants appear
- Weather Conditions: Temperature, recent rain
- Species: If identifiable
- Treatment Response: What worked/didn’t
Digital Tracking Option:
Text sightings to (206) 571 7580 with:
- Photo
- Location
- Date/time
- Weather notes
We maintain seasonal records for repeat customers to predict and prevent issues.
When to Take Action This Season
RIGHT NOW (Regardless of Season):
- Active trail inside
- Swarm indoors
- Frass discovery
- Call: (206) 571 7580 for emergency service
THIS MONTH (Preventive):
- No current activity
- Previous year issues
- Neighbor infestations
- Schedule: Preventive treatment
NEXT MONTH (Planning):
- Seasonal preparation
- Routine maintenance
- Book: Advance appointment for optimal timing
Seasonal Success Stories
Ballard Homeowner (Spring Prevention):
“After years of May ant invasions, we scheduled AMPM’s March preventive treatment. Zero ants all season. The timing was everything.”
Bellevue Restaurant (Summer Management):
“Our patio dining area was ant central every July. AMPM’s June barrier treatment and monthly monitoring kept us completely ant free during peak season.”
West Seattle Family (Fall Resolution):
*”Every September, ants marched into our kitchen with the first rain. Fall exclusion treatment plus crawl space moisture control finally solved our 5 year pattern.”*
Get Ahead of the Season
Don’t wait for ants to announce their presence. Seattle’s predictable ant patterns allow for proactive prevention.
Current Season Action Items:
If It’s March-April:
- Schedule preventive barrier treatment
- Conduct moisture assessment
- Seal exterior entry points
- Book Spring Prevention
If It’s May-June:
- Monitor for swarms
- Address any activity immediately
- Consider mid-season refresh
- Emergency Swarm Response
If It’s July-December:
View our main service page for current seasonal recommendations
Stay Informed Year-Round
Seasonal Alert System:
Text “SEATTLEANTS” to (206) 571 7580 to receive:
- Seasonal emergence alerts
- Swarm warnings for your area
- Preventive timing reminders
- Special seasonal offers
Neighborhood Monitoring:
We track ant activity across Seattle neighborhoods and provide localized alerts to customers.
Take Control of Your Ant Season
Seattle’s ant patterns don’t have to dictate your home’s comfort. With proper timing and professional assistance, you can stay ahead of seasonal infestations.
Current Season Consultation: (206) 571 7580
- Free seasonal assessment
- Timing recommendations
- Preventive scheduling
Learn About Year-Round Solutions:
Visit Our Ant Control Services Page
- Seasonal treatment options
- Maintenance plans
- Emergency services
- Customer reviews
2024 Seasonal Service Calendar
| Month | Primary Action | DIY Tasks | Professional Service |
|---|---|---|---|
| Jan-Feb | Planning | Research, seal indoors | Assessments, indoor treatments |
| Mar | Prevention | Clean gutters, trim plants | Barrier treatments, inspections |
| Apr | Early Action | Monitor for scouts | Carpenter ant prevention |
| May | Swarm Prep | Document activity | Swarm response readiness |
| Jun | Peak Management | Sanitation, monitoring | Active infestation treatment |
| Jul-Aug | Maintenance | Landscape management | Barrier refresh, monitoring |
| Sep | Fall Prep | Seal entries, clean | Preventive treatments |
| Oct-Nov | Winter Prep | Moisture control | Crawl space treatments |
| Dec | Assessment | Review year | Planning for next season |
Serving Seattle Through Every Season Since 2005
Seasonal Experts • Local Knowledge • Predictive Prevention
(206) 571 7580