Portland, Maine Weather
Cicadas claim the afternoon. Day 15 of summer. Read this microseason across nine climate regions →
Portland weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 5Overcast——82°62°—
- MondayJul 6Overcast——73°61°-9°
- TuesdayJul 7Rain33%0.91″61°56°-12°
- WednesdayJul 8Overcast17%—79°53°+18°
- ThursdayJul 9Overcast15%—89°62°+10°
- FridayJul 10Overcast44%—83°69°-6°
- SaturdayJul 11Overcast14%—78°58°-5°
AQI 52 (Moderate), driven by PM2.5. AQI up 13 over the last 6 hours (gradual rise). PM2.5 at 17.9 µg/m³ (AQI 67) with a 0.96 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 7 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 36 now. With UV 6.4 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 31 around 1 PM.
- Present
- AQI 36
- UV peak
- 6.4 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 31
PM × Wind × Precip
PM2.5 at 17.9 µg/m³ (AQI 67) with a 0.96 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.96
- 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).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:00 PM
- Moonset
- 10:48 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Portland at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: May 8 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP codes: 04101, 04102, 04103, 04109
16-Day Forecast — Portland
- Sun82°62°1%
- Mon73°61°5%
- Tue61°56°33%
- Wed79°53°17%
- Thu89°62°15%
- Fri83°69°44%
- Sat78°58°14%
- Sun75°59°10%
- Mon74°56°18%
- Tue80°57°19%
- Wed91°70°18%
- Thu85°63°27%
- Fri90°60°29%
- Sat93°68°21%
- Sun80°63°26%
- Mon81°64°42%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Portland
Right now in the garden
Peak growing season
As of July 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.
Microseason · July 1–5
Cicadas claim the afternoon
Annual cicada buzz begins, peaking in the heat of the day.
Day 186 of 365 · Wedge 37 of 72
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
July is Portland's warmest stretch (~70°F) and January its coldest (~24°F); precipitation crests in October at 5.3 inches and ebbs in July to 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
In Portland, NOAA NCEI 1991-2020 normals put January near 24°F and July near 70°F — a 46°F seasonal arc — with about 48.1 inches of precipitation over 80 rainy or snowy days.
No season owns Portland's rain: October reaches 5.3 inches across 6.8 days and July keeps 3.4 inches on 6.7, an even spread through Portland's year. That lines Portland up with places like South Portland, ME, Westbrook, ME and Falmouth Foreside, ME, fed by overlapping storm tracks.
Around late-May, Portland sheds its freezing nights — kale, peas, spinach, and parsnips go into Portland's beds. Portland's heat-lovers — tomatoes, peppers, squash — hold off until Portland's frost risk clears, 10-14 days on. The season ends by early-October in Portland, once hard frosts set back in. Portland's low ground holds frost later into spring than Portland's benches, which run 3-5 days ahead.
Similar climates: South Portland, ME, Westbrook, ME, Falmouth Foreside, ME, Cumberland Center, ME, South Windham, ME.
Naturalist notes
Late May brings the first ruby-throated hummingbirds to Portland's gardens, their migration timed with the blooming of native honeysuckle.
Apple trees across the region typically reach full bloom by mid-May, marking the transition from spring's cool nights to the approaching warmth of early summer.
Frequently asked
- When does it freeze in Portland?
- In Portland, expect the last spring frost near mid-May; Portland's first autumn frost comes around mid-October.
- What is the rainy season in Portland?
- Portland sees its heaviest rain in October (around 5.3 inches), part of roughly 48 inches a year.
- What is the warmest month in Portland?
- July is Portland's warmest month, averaging about 70°F.
- What is the coldest month in Portland?
- Portland bottoms out in January, with a mean near 24°F.
- When can I start a vegetable garden in Portland?
- Portland's last frost (mid-May) cues hardy greens; in Portland, hold heat-lovers two weeks past.
- How many rainy days does Portland get?
- Expect roughly 80 wet days a year in Portland.
- What hardiness zone is Portland?
- Portland's USDA zone comes from its January mean (24°F); enter the ZIP on the USDA lookup for the number.
- What is the 10-day forecast for Portland?
- Portland's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Portland?
- See this week's day-by-day rain chances for Portland in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Portland?
- Current conditions for Portland and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Portland forecast updated?
- The Portland forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Portland?
- Today's sunrise and sunset times for Portland are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Portland?
- The next few days in Portland's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Portland, Maine occupies a warm-summer humid continental zone, with January means near 24°F and July around 70°F — a 46°F swing.
Yearly precipitation in Portland totals around 48 inches, spread over about 80 days of rain or snow.
The 46°F gap between Portland's summer and winter, at 43.7°N, shapes Portland's frost calendar.
ZIP codes in Portland
- 04101
- 04102
- 04103
- 04108
- 04109
- 04019
- 04104
- 04112
- 04116
- 04122
- 04123
- 04124