Glenn Dale, Maryland climate: Normal weather by month, frost dates and records
Glenn Dale's normal year runs from 22°F January nights to 89°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.7°C, January lows of −6°C, July highs of 31°C.
- NOAA stationGlenn Dale Bell Station
- Station IDUSC00183675
- Location38.97°N 76.80°W
- Elevation150 ft (46 m)
- From the center1 miles
- Population (census place)14,896
On October 14, the normal high in Glenn Dale is 69°F and the normal low 44°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Glenn Dale.
- Jan 44° 22°
- Feb 47° 23°
- Mar 55° 31°
- Apr 66° 41°
- May 75° 51°
- Jun 83° 61°
- Jul 89° 66°
- Aug 87° 65°
- Sep 79° 57°
- Oct 68° 44°
- Nov 57° 33°
- Dec 48° 27°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Glenn Dale each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 22°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 44°F | 22°F | 32.7°F | – | <1 | 25 | 9 h 40 min |
| February | 47°F | 23°F | 35.0°F | – | <1 | 22 | 10 h 40 min |
| March | 55°F | 31°F | 43.0°F | – | <1 | 18 | 11 h 50 min |
| April | 66°F | 41°F | 53.5°F | – | 1 | 6 | 13 h 10 min |
| May | 75°F | 51°F | 63.0°F | – | 3 | <1 | 14 h 20 min |
| June | 83°F | 61°F | 71.8°F | – | 7 | <1 | 14 h 50 min |
| July | 89°F | 66°F | 77.3°F | – | 14 | <1 | 14 h 40 min |
| August | 87°F | 65°F | 75.9°F | – | 11 | <1 | 13 h 40 min |
| September | 79°F | 57°F | 68.4°F | – | 3 | <1 | 12 h 30 min |
| October | 68°F | 44°F | 55.9°F | – | <1 | 4 | 11 h 20 min |
| November | 57°F | 33°F | 45.0°F | – | <1 | 14 | 10 h 10 min |
| December | 48°F | 27°F | 37.4°F | – | <1 | 23 | 9 h 30 min |
| Year (annual) | 66°F | 44°F | 54.9°F | – | 39 | 112 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 7°C | −6°C | 0.4°C |
| February | 8°C | −5°C | 1.7°C |
| March | 13°C | 0°C | 6.1°C |
| April | 19°C | 5°C | 11.9°C |
| May | 24°C | 11°C | 17.2°C |
| June | 28°C | 16°C | 22.1°C |
| July | 31°C | 19°C | 25.2°C |
| August | 31°C | 18°C | 24.4°C |
| September | 26°C | 14°C | 20.2°C |
| October | 20°C | 7°C | 13.3°C |
| November | 14°C | 1°C | 7.2°C |
| December | 9°C | −3°C | 3.0°C |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Beltsville (8 miles away), gets 16 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00183675; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Glenn Dale?
Normal highs sit between 65°F and 85°F in April, May, June, September and October.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00183675.
When is the last frost in Glenn Dale?
In Glenn Dale, the last spring frost (32°F) comes after April 22 in half of years and after May 9 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 7 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 221 year in 10 after May 9; 9 in 10 after April 3
- First autumn frost, half of years before
- October 221 year in 10 before October 7; 9 in 10 before November 6
NOAA puts the median frost-free season at 183 days, and the season without a hard freeze (28°F) at 207 days.
A hard freeze (28°F) comes after April 7 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Glenn Dale in zone 7b across its 2 ZIP code areas (7b in 20769, the largest).
Frost dates for every NOAA station in Maryland · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00183675; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Glenn Dale ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Glenn Dale's 2 ZIP code areas are all in zone 7b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Glenn Dale?
In a normal year in Glenn Dale, 39 days a year reach 90°F (1 of them 100°F or more) and 112 nights fall to 32°F or colder.
- Days at 90°F or more
- 39a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 112a normal year
- Days that stay below freezing
- 9high of 32°F or less
The highest temperature in this station's record (since 1921) is 106°F, on July 10, 1936; the lowest is −23°F, on January 28, 1935.
The wettest calendar year on that record is 1948, with 60.44 in; the snowiest season is 1957–58, with 52.8 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00183675; records: ACIS (NOAA Regional Climate Centers), station USC00183675. Records use complete months only; a month missing more than three days is left out.
How sunny is Glenn Dale?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Glenn Dale, 4.2 kWh per square metre a day. July is the sunniest month (84%) and January the cloudiest (71%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 71% | 2.2 |
| February | 72% | 3.0 |
| March | 72% | 4.0 |
| April | 75% | 5.2 |
| May | 76% | 5.8 |
| June | 82% | 6.4 |
| July | 84% | 6.3 |
| August | 82% | 5.6 |
| September | 79% | 4.5 |
| October | 76% | 3.4 |
| November | 76% | 2.5 |
| December | 71% | 1.9 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Glenn Dale need?
A normal year in Glenn Dale brings 4,846 heating degree days, 10% fewer than the median U.S. place (5,373), and 1,202 cooling degree days, 32% more than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,762 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,000 | 0 |
| February | 841 | 0 |
| March | 684 | 2 |
| April | 361 | 16 |
| May | 134 | 72 |
| June | 20 | 225 |
| July | 0 | 381 |
| August | 1 | 339 |
| September | 48 | 149 |
| October | 298 | 16 |
| November | 603 | 2 |
| December | 857 | 0 |
| Year (annual) | 4,846 | 1,202 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00183675. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Glenn Dale's climate compare?
Glenn Dale is warmer than 7 of the other 25 places with their own NOAA record in Maryland. Across the 7,247 U.S. stations with normals, its annual mean of 54.9°F is warmer than 60%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Glenn Dale share this climate record?
7 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Bowie, MDalso near: Upper Marlboro (7 mi, 56.0°F a year); Beltsville (12 mi, 55.9°F a year)58,421 people · 4 mi E
- Crofton, MD29,878 people · 7 mi NE
- Seabrook, MD18,495 people · 3 mi W
- Lanham, MD11,956 people · 2 mi W
- Mitchellville, MD11,325 people · 2 mi S
- Fairwood, MD8,108 people · 2 mi SE
- Woodmore, MD4,710 people · 3 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Glenn Dale's climate
What is the coldest month in Glenn Dale?
January, with a normal high of 44°F and a normal low of 22°F. The warmest is July (89°F by day, 66°F at night).
Does it snow in Glenn Dale?
Yes. NOAA publishes no 1991-2020 snowfall normal for Glenn Dale's NOAA station; the nearest record that keeps one, Beltsville (8 miles away), records 16 inches of snow in a normal year.
What plant hardiness zone is Glenn Dale in?
The USDA's 2023 map puts Glenn Dale in zone 7b across its 2 ZIP code areas (7b in 20769, the largest).
How late can frost come in Glenn Dale?
In half of years the last 32°F night comes after April 22; in one year in ten it comes after May 9. Waiting until May 9 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Maryland climateThe statewide normals and every place in the state
- Beltsville, MD8 miles from this station, 55.9°F a year
- Upper Marlboro, MD8 miles from this station, 56.0°F a year
- Laurel, MD9 miles from this station, 57.1°F a year
- National Arboretum DC, MD10 miles from this station, 58.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made