Westbrook, Maine Weather
Fireflies rise from the lawn. Day 78 of spring. Read this microseason across nine climate regions →
Westbrook weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Clear——83°52°—
- FridayJun 5Overcast——83°59°0°
- SaturdayJun 6Light Rain35%0.07″77°56°-6°
- SundayJun 7Drizzle65%0.02″80°52°+3°
- MondayJun 8Overcast19%—80°49°0°
- TuesdayJun 9Overcast——86°58°+6°
- WednesdayJun 10Overcast——92°63°+6°
PM2.5 at 11.9 µg/m³ (AQI 56) with a 0.76 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust. AQI up 30 in the last 6 hours — air quality is degrading.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 50. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 50
- UV peak
- 0.0 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 6
PM × Wind × Precip
PM2.5 at 11.9 µg/m³ (AQI 56) with a 0.76 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.76
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
The higher the clouds, the finer the weather.
- Moonrise
- 3:51 AM
- Moonset
- 1:35 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Westbrook at a glance
- Today vs. normal: 71°F — typical for the season
- Last frost: May 8 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Westbrook
SPC has placed Westbrook in the Marginal Risk category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3MRGLMarginal Risk
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | — | — |
| May | lettuce, peas, spinach, radishes | lettuce, peas, radishes |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | tomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | — | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Westbrook's warmest month is July (~70°F mean) and its coldest is January (~24°F). Rainfall peaks in October (5.3 inches) and bottoms out in July (3.4 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 24° | 3.5″ | 7 |
| February | 26° | 3.5″ | 7 |
| March | 34° | 4.1″ | 7 |
| April | 45° | 4.4″ | 7 |
| May | 55° | 3.7″ | 7 |
| June | 64° | 4.2″ | 7 |
| July | 70° | 3.4″ | 7 |
| August | 69° | 3.6″ | 5 |
| September | 62° | 3.8″ | 5 |
| October | 50° | 5.3″ | 7 |
| November | 40° | 4.3″ | 7 |
| December | 30° | 4.5″ | 8 |
Regional context
Westbrook sits within a warm-summer humid continental climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Portland, ME, Lewiston, ME, Bangor, ME, South Portland, ME, Auburn, ME.
Frequently asked
- When does it freeze in Westbrook?
- Westbrook's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Westbrook?
- October is the wettest month with about 5.3 inches of rain on average; the city receives roughly 48 inches annually.
- What is the warmest month in Westbrook?
- July is typically warmest, averaging about 70°F.
- What is the coldest month in Westbrook?
- January is typically coldest, averaging about 24°F.
- When can I start a vegetable garden in Westbrook?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-May); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Westbrook get?
- Westbrook averages about 80 rainy days per year.
- What hardiness zone is Westbrook?
- Westbrook's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Westbrook, Maine sits in a warm-summer humid continental climate zone. January means hover near 24°F while July averages 70°F — a 46°F seasonal swing.
Across the year, Westbrook receives about 48 inches of precipitation spread over roughly 80 rainy days.
The rhythm of the year is set by latitude (43.7°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.