Upper Marlboro, Maryland climate: Normal weather by month, frost dates and records
Upper Marlboro's normal year runs from 25°F January nights to 88°F July afternoons, with 45.0 inches of precipitation and 16 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.3°C, January lows of −4°C, July highs of 31°C, 1,143 mm of precipitation a year.
- NOAA stationUpper Marlboro (3 mi NNW)
- Station IDUSC00189070
- Location38.85°N 76.77°W
- Elevation130 ft (40 m)
- Population718
On October 23, the normal high in Upper Marlboro is 66°F and the normal low 43°F, and the chance of measurable rain or snow is 25%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Upper Marlboro.
- Jan 44° 25°
- Feb 47° 26°
- Mar 55° 33°
- Apr 67° 44°
- May 75° 54°
- Jun 84° 63°
- Jul 88° 67°
- Aug 86° 65°
- Sep 80° 58°
- Oct 69° 46°
- Nov 58° 36°
- Dec 48° 29°
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 Upper Marlboro each month?
July is the warmest month, with normal highs of 88°F; January the coldest, with normal lows of 25°F. The most precipitation falls in September (4.51 in), the least in February (2.66 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 44°F | 25°F | 34.3°F | 2.96 | 5.7 | 10 | <1 | 25 | 9 h 40 min |
| February | 47°F | 26°F | 36.4°F | 2.66 | 6.3 | 9 | <1 | 23 | 10 h 40 min |
| March | 55°F | 33°F | 43.8°F | 3.92 | 1.7 | 10 | <1 | 16 | 11 h 50 min |
| April | 67°F | 44°F | 55.0°F | 3.38 | 0.0 | 10 | <1 | 3 | 13 h 10 min |
| May | 75°F | 54°F | 64.1°F | 4.11 | 0.0 | 10 | 2 | <1 | 14 h 20 min |
| June | 84°F | 63°F | 73.1°F | 4.20 | 0.0 | 11 | 7 | <1 | 14 h 50 min |
| July | 88°F | 67°F | 77.7°F | 4.22 | 0.0 | 9 | 11 | <1 | 14 h 40 min |
| August | 86°F | 65°F | 75.8°F | 4.12 | 0.0 | 9 | 9 | <1 | 13 h 40 min |
| September | 80°F | 58°F | 69.0°F | 4.51 | 0.0 | 8 | 3 | <1 | 12 h 30 min |
| October | 69°F | 46°F | 57.2°F | 4.13 | 0.0 | 8 | <1 | 2 | 11 h 20 min |
| November | 58°F | 36°F | 46.7°F | 3.25 | 0.0 | 7 | <1 | 13 | 10 h 10 min |
| December | 48°F | 29°F | 38.4°F | 3.55 | 2.2 | 10 | <1 | 22 | 9 h 30 min |
| Year (annual) | 67°F | 45°F | 56.0°F | 45.01 | 15.9 | 111 | 32 | 103 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 7°C | −4°C | 1.3°C | 75 mm | 14 cm |
| February | 8°C | −3°C | 2.4°C | 68 mm | 16 cm |
| March | 13°C | 0°C | 6.6°C | 100 mm | 4 cm |
| April | 19°C | 6°C | 12.8°C | 86 mm | 0 cm |
| May | 24°C | 12°C | 17.8°C | 104 mm | 0 cm |
| June | 29°C | 17°C | 22.8°C | 107 mm | 0 cm |
| July | 31°C | 20°C | 25.4°C | 107 mm | 0 cm |
| August | 30°C | 19°C | 24.3°C | 105 mm | 0 cm |
| September | 27°C | 15°C | 20.6°C | 115 mm | 0 cm |
| October | 20°C | 8°C | 14.0°C | 105 mm | 0 cm |
| November | 14°C | 2°C | 8.2°C | 83 mm | 0 cm |
| December | 9°C | −2°C | 3.6°C | 90 mm | 6 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00189070; 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 Upper Marlboro?
Normal highs sit between 65°F and 85°F in April, May, June, September and October. Of those, September has the fewest days with rain (8).
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 USC00189070.
When is the last frost in Upper Marlboro?
In Upper Marlboro, the last spring frost (32°F) comes after April 9 in half of years and after April 24 in one year in ten; the first autumn frost comes before October 29 in half of years and before October 14 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 91 year in 10 after April 24; 9 in 10 after March 27
- First autumn frost, half of years before
- October 291 year in 10 before October 14; 9 in 10 before November 11
NOAA puts the median frost-free season at 203 days, and the season without a hard freeze (28°F) at 225 days.
A hard freeze (28°F) comes after March 30 in half of springs and before November 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Upper Marlboro in zone 7b in ZIP code 20772, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Upper Marlboro's NOAA station is in zone 7b: the coldest night of a typical year reaches 5°F (23 complete years).
Frost dates for every NOAA station in Maryland · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00189070; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Upper Marlboro?
In a normal year in Upper Marlboro, 32 days a year reach 90°F (1 of them 100°F or more), 103 nights fall to 32°F or colder and 111 days bring measurable precipitation.
- Days at 90°F or more
- 32a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 103a normal year
- Days that stay below freezing
- 9high of 32°F or less
- Days with 0.01 inch of precipitation
- 111a normal year
- Days with 1 inch of snow or more
- 4a normal year
The highest temperature in this station's record (since 1956) is 105°F, on July 8, 2012; the lowest is −12°F, on January 22, 1984.
The wettest calendar year on that record is 2003, with 59.88 in; the snowiest season is 2009–10, with 58.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00189070; records: ACIS (NOAA Regional Climate Centers), station USC00189070. Records use complete months only; a month missing more than three days is left out.
How sunny is Upper Marlboro?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Upper Marlboro, 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 Upper Marlboro need?
A normal year in Upper Marlboro brings 4,546 heating degree days, 15% fewer than the median U.S. place (5,373), and 1,284 cooling degree days, 42% 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 3,960 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 952 | 0 |
| February | 802 | 0 |
| March | 661 | 2 |
| April | 323 | 23 |
| May | 116 | 90 |
| June | 15 | 258 |
| July | 0 | 392 |
| August | 1 | 335 |
| September | 37 | 159 |
| October | 265 | 23 |
| November | 549 | 2 |
| December | 825 | 0 |
| Year (annual) | 4,546 | 1,284 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00189070. 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.
Has Upper Marlboro been warmer than normal lately?
Over 48 complete years from 1957 to 2015, the station's annual mean temperature rose at a fitted 4.3°F per century (+0.24°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Upper Marlboro's climate compare?
Upper Marlboro is warmer than 12 of the other 25 places with their own NOAA record in Maryland, and wetter than 9. Across the 7,247 U.S. stations with normals, its annual mean of 56.0°F is warmer than 64%.
In the Köppen classification computed from these normals, Upper Marlboro is Cfa: temperate, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Upper Marlboro share this climate record?
12 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.
- Kettering, MD13,866 people · 3 mi NW
- Brock Hall, MD13,400 people · 1 mi E
- Marlboro Village, MD9,200 people · 1 mi S
- Chesapeake Beach, MD6,504 people · 16 mi SE
- Deale, MD5,182 people · 13 mi E
- Marlboro Meadows, MD4,003 people · 3 mi E
- Brown Station, MD3,918 people · 2 mi W
- Owings, MD2,475 people · 13 mi SE
- Dunkirk, MD2,319 people · 11 mi SE
- North Beach, MD2,178 people · 16 mi SE
- Queen Anne, MD1,374 people · 5 mi NE
- Friendship, MD336 people · 13 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 Upper Marlboro's climate
What is the coldest month in Upper Marlboro?
January, with a normal high of 44°F and a normal low of 25°F. The warmest is July (88°F by day, 67°F at night).
Does it snow in Upper Marlboro?
Yes: 16 inches in a normal year, falling on 7 days with 0.1 inch or more, the most in February (6.3 inches).
What is the rainiest month in Upper Marlboro?
September, with 4.51 in of precipitation in a normal year; the driest is February with 2.66 in.
What plant hardiness zone is Upper Marlboro in?
The USDA's 2023 map puts Upper Marlboro in zone 7b in ZIP code 20772, the nearest ZIP area. By the same method at Upper Marlboro's NOAA station, the coldest night of a typical year reaches 5°F (23 years, 1991-2020): zone 7b.
How late can frost come in Upper Marlboro?
In half of years the last 32°F night comes after April 9; in one year in ten it comes after April 24. Waiting until April 24 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Maryland climateThe statewide normals and every place in the state
- Glenn Dale, MD8 miles from this station, 54.9°F a year
- National Arboretum DC, MD12 miles from this station, 58.3°F a year
- Oxon Hill, MD13 miles from this station, 57.1°F a year
- Washington, DC14 miles from this station, 59.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made