Greenbelt, Maryland Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Greenbelt weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Light Rain23%0.09″101°78°—
- SundayJul 5Rain49%0.21″96°74°-5°
- MondayJul 6Heavy Drizzle81%—85°74°-11°
- TuesdayJul 7Thunderstorm81%0.16″89°71°+4°
- WednesdayJul 8Rain37%0.37″79°69°-10°
- ThursdayJul 9Overcast13%—93°68°+14°
- FridayJul 10Light Drizzle41%0.05″94°72°+1°
AQI 123 (Unhealthy for Sensitive Groups), driven by Ozone. AQI up 68 in the last 6 hours — air quality is degrading. Ozone at AQI 108 — peak already passed at 1 PM under clear skies. Levels should ease through evening.
CAUTION Sensitive groups (children, elderly, respiratory conditions) should limit prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 108 — peak already passed at 1 PM under clear skies. Levels should ease through evening.
- Present
- AQI 108
- UV peak
- 2.0 at earlier today
- Sky at peak
- clear
- Projected peak
- AQI 108
PM × Wind × Precip
PM2.5 at 9.2 µg/m³, PM10 at 10.2 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.90
- Wind
- light
- Recent rain
- 1h in last 6h
- Pattern
- background
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
- 10:59 PM
- Moonset
- 10:12 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Greenbelt at a glance
- Today vs. normal: 28°F above the seasonal normal for this latitude
- Last frost: April 10 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP codes: 20770, 20771
16-Day Forecast — Greenbelt
- Sat101°78°23%
- Sun96°74°49%
- Mon85°74°81%
- Tue89°71°81%
- Wed79°69°37%
- Thu93°68°13%
- Fri94°72°41%
- Sat93°69°37%
- Sun82°70°22%
- Mon80°69°20%
- Tue88°66°18%
- Wed94°69°33%
- Thu95°70°37%
- Fri92°74°42%
- Sat95°71°44%
- Sun91°70°46%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 4, 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 — Greenbelt
SPC has placed Greenbelt in the Enhanced Risk category for severe thunderstorms today.
- TODAYENHEnhanced Risk
- TOMORROWSLGTSlight Risk
- DAY 3TSTMGeneral Thunderstorms
Numerous severe storms likely. Tornadoes, large hail, and damaging wind gusts possible across the area. Track NWS warnings if storms develop.
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.
Microseason · July 1–5
Cicadas claim the afternoon
Annual cicada buzz begins, peaking in the heat of the day.
Day 185 of 365 · Wedge 37 of 72
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Greenbelt peaks at about 78°F in July and bottoms near 32°F in January; August brings the heaviest rain (4.2 inches) and October the least (2.6 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 32° | 3.3″ | 13 |
| February | 35° | 2.8″ | 12 |
| March | 44° | 3.4″ | 15 |
| April | 55° | 3.7″ | 17 |
| May | 63° | 3.5″ | 18 |
| June | 72° | 3.9″ | 17 |
| July | 78° | 3.2″ | 17 |
| August | 77° | 4.2″ | 18 |
| September | 70° | 3.4″ | 14 |
| October | 59° | 2.6″ | 11 |
| November | 46° | 3.6″ | 12 |
| December | 37° | 3.9″ | 14 |
Regional context
Greenbelt swings from 32°F in January to 78°F in July (46°F) per NOAA NCEI 1991-2020 normals; precipitation in Greenbelt runs about 41.5 inches on roughly 175 measurable days.
Greenbelt's precipitation spreads evenly: August peaks at 4.2 inches on 17.8 wet days, while October holds 2.6 inches over 11.1 — no month dominates Greenbelt's rain calendar. That lines Greenbelt up with places like Berwyn Heights, MD, New Carrollton, MD and Seabrook, MD, fed by overlapping storm tracks.
Greenbelt reaches its last hard frost near mid-April; that is the cue for peas, lettuce, spinach, and radishes. Heat-demanding starts go out a fortnight on in Greenbelt, after the soil warms and cold snaps clear. The season ends by mid-November in Greenbelt, once hard frosts set back in. Greenbelt's low ground holds frost later into spring than Greenbelt's benches, which run 3-5 days ahead.
Similar climates: Berwyn Heights, MD, New Carrollton, MD, Seabrook, MD, College Park, MD, East Riverdale, MD.
Frequently asked
- When does it freeze in Greenbelt?
- Frost typically leaves Greenbelt by mid-April and returns to Greenbelt near mid-November.
- What is the rainy season in Greenbelt?
- Rainfall in Greenbelt peaks in August near 4.2 inches, out of about 42 inches annually.
- What is the warmest month in Greenbelt?
- Greenbelt peaks in July, when the mean runs near 78°F.
- What is the coldest month in Greenbelt?
- January is Greenbelt's coldest month, averaging about 32°F.
- When can I start a vegetable garden in Greenbelt?
- In Greenbelt, sow peas and hardy greens around mid-April; Greenbelt's tomatoes and peppers wait two weeks more.
- How many rainy days does Greenbelt get?
- Expect roughly 175 wet days a year in Greenbelt.
- What hardiness zone is Greenbelt?
- Since January in Greenbelt averages 32°F, Greenbelt's USDA zone follows that floor — confirm it by ZIP.
- What is the 10-day forecast for Greenbelt?
- Greenbelt'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 Greenbelt?
- See this week's day-by-day rain chances for Greenbelt in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Greenbelt?
- Current conditions for Greenbelt and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Greenbelt forecast updated?
- The Greenbelt forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Greenbelt?
- Today's sunrise and sunset times for Greenbelt 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 Greenbelt?
- The next few days in Greenbelt's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Set in a warm-summer humid continental zone, Greenbelt, Maryland swings from 32°F in the heart of winter to 78°F at midsummer — a 46°F arc.
In a typical year Greenbelt records about 42 inches of precipitation on around 175 days.
Greenbelt's 46°F range, set by its 39.0°N position, drives frost timing and what thrives in Greenbelt.
ZIP codes in Greenbelt
- 20770
- 20768