Mechanicsville, Maryland climate: Normal weather by month, frost dates and records
Mechanicsville's normal year runs from 25°F January nights to 85°F July afternoons, with 48.1 inches of precipitation and 15 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.9°C, January lows of −4°C, July highs of 30°C, 1,222 mm of precipitation a year.
- NOAA stationMechanicsville (5 mi NE)
- Station IDUSC00185865
- Location38.49°N 76.73°W
- Elevation100 ft (31 m)
- From the center5 miles
- Population (census place)1,521
On October 23, the normal high in Mechanicsville is 64°F and the normal low 43°F, and the chance of measurable rain or snow is 28%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Mechanicsville.
- Jan 44° 25°
- Feb 48° 26°
- Mar 56° 33°
- Apr 67° 43°
- May 74° 52°
- Jun 82° 61°
- Jul 85° 66°
- Aug 83° 64°
- Sep 77° 58°
- Oct 66° 46°
- Nov 57° 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 Mechanicsville each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 25°F. The most precipitation falls in September (4.87 in), the least in February (2.97 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 44°F | 25°F | 34.5°F | 3.29 | 5.0 | 10 | <1 | 24 | 9 h 50 min |
| February | 48°F | 26°F | 36.9°F | 2.97 | 6.2 | 9 | <1 | 21 | 10 h 40 min |
| March | 56°F | 33°F | 44.2°F | 4.24 | 1.8 | 10 | <1 | 16 | 11 h 50 min |
| April | 67°F | 43°F | 54.9°F | 3.31 | 0.1 | 10 | 1 | 4 | 13 h 10 min |
| May | 74°F | 52°F | 62.9°F | 4.32 | 0.0 | 11 | 1 | <1 | 14 h 10 min |
| June | 82°F | 61°F | 71.2°F | 4.19 | 0.0 | 10 | 3 | <1 | 14 h 50 min |
| July | 85°F | 66°F | 75.6°F | 4.57 | 0.0 | 10 | 7 | <1 | 14 h 40 min |
| August | 83°F | 64°F | 73.8°F | 4.84 | 0.0 | 9 | 4 | <1 | 13 h 40 min |
| September | 77°F | 58°F | 67.2°F | 4.87 | 0.0 | 9 | 1 | <1 | 12 h 30 min |
| October | 66°F | 46°F | 55.9°F | 4.18 | 0.0 | 8 | <1 | 1 | 11 h 20 min |
| November | 57°F | 36°F | 46.4°F | 3.34 | 0.0 | 8 | <1 | 12 | 10 h 10 min |
| December | 48°F | 29°F | 38.3°F | 3.99 | 2.0 | 9 | <1 | 21 | 9 h 30 min |
| Year (annual) | 66°F | 45°F | 55.2°F | 48.11 | 15.1 | 115 | 16 | 98 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 7°C | −4°C | 1.4°C | 84 mm | 13 cm |
| February | 9°C | −3°C | 2.7°C | 75 mm | 16 cm |
| March | 13°C | 0°C | 6.8°C | 108 mm | 5 cm |
| April | 20°C | 6°C | 12.7°C | 84 mm | 0 cm |
| May | 23°C | 11°C | 17.2°C | 110 mm | 0 cm |
| June | 28°C | 16°C | 21.8°C | 106 mm | 0 cm |
| July | 30°C | 19°C | 24.2°C | 116 mm | 0 cm |
| August | 29°C | 18°C | 23.2°C | 123 mm | 0 cm |
| September | 25°C | 14°C | 19.6°C | 124 mm | 0 cm |
| October | 19°C | 8°C | 13.3°C | 106 mm | 0 cm |
| November | 14°C | 2°C | 8.0°C | 85 mm | 0 cm |
| December | 9°C | −2°C | 3.5°C | 101 mm | 5 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00185865; 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 Mechanicsville?
Normal highs sit between 65°F and 85°F in April, May, June, August, September and October. Of those, October 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 USC00185865.
When is the last frost in Mechanicsville?
In Mechanicsville, the last spring frost (32°F) comes after April 17 in half of years and after May 2 in one year in ten; the first autumn frost comes before October 27 in half of years and before October 12 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 171 year in 10 after May 2; 9 in 10 after March 31
- First autumn frost, half of years before
- October 271 year in 10 before October 12; 9 in 10 before November 9
NOAA puts the median frost-free season at 195 days, and the season without a hard freeze (28°F) at 219 days.
A hard freeze (28°F) comes after April 2 in half of springs and before November 6 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Mechanicsville in zone 7b in ZIP code 20659, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Mechanicsville's NOAA station is in zone 7b: the coldest night of a typical year reaches 6°F (29 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 USC00185865; 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 Mechanicsville?
In a normal year in Mechanicsville, 16 days a year reach 90°F, 98 nights fall to 32°F or colder and 115 days bring measurable precipitation.
- Days at 90°F or more
- 16a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 98a normal year
- Days that stay below freezing
- 8high of 32°F or less
- Days with 0.01 inch of precipitation
- 115a normal year
- Days with 1 inch of snow or more
- 4a normal year
The highest temperature in this station's record (since 1974) is 103°F, on July 16, 1980; the lowest is −9°F, on February 5, 1996.
The wettest calendar year on that record is 2020, with 80.86 in; the snowiest season is 1995–96, with 61.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00185865; records: ACIS (NOAA Regional Climate Centers), station USC00185865. Records use complete months only; a month missing more than three days is left out.
How sunny is Mechanicsville?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Mechanicsville, 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 Mechanicsville need?
A normal year in Mechanicsville brings 4,589 heating degree days, 15% fewer than the median U.S. place (5,373), and 1,029 cooling degree days, 13% 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 3,649 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 945 | 0 |
| February | 787 | 0 |
| March | 645 | 2 |
| April | 324 | 21 |
| May | 133 | 66 |
| June | 17 | 203 |
| July | 0 | 329 |
| August | 2 | 273 |
| September | 53 | 119 |
| October | 297 | 15 |
| November | 559 | 1 |
| December | 826 | 0 |
| Year (annual) | 4,589 | 1,029 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00185865. 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 Mechanicsville been warmer than normal lately?
2025 averaged 55.2°F, equal to the 1991-2020 normal of 55.2°F. 3 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 56.3°F | +1.1°F | 47.40 | 6.3 |
| 2022 | 55.1°F | −0.1°F | 51.24 | 16.2 |
| 2023 | 56.4°F | +1.2°F | 43.06 | 0.0 |
| 2024 | 56.8°F | +1.6°F | 37.07 | – |
| 2025 | 55.2°F | at normal | 41.75 | 21.9 |
Over 39 complete years from 1985 to 2025, the station's annual mean temperature rose at a fitted 4.2°F per century (+0.23°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00185865; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Mechanicsville's climate compare?
Mechanicsville is warmer than 8 of the other 25 places with their own NOAA record in Maryland, and wetter than 20. Across the 7,247 U.S. stations with normals, its annual mean of 55.2°F is warmer than 61%.
In the Köppen classification computed from these normals, Mechanicsville 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 Mechanicsville 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.
- Colonial Beach, VA4,038 people · 21 mi SW
- Golden Beach, MD3,953 people · 1 mi E
- Dahlgren, VA3,417 people · 21 mi SW
- Huntingtown, MD2,634 people · 10 mi NE
- Prince Frederick, MD2,404 people · 8 mi NE
- Hughesville, MD2,280 people · 4 mi NW
- Charlotte Hall, MD1,448 people · 4 mi SW
- Aquasco, MD672 people · 7 mi N
- Dahlgren Center, VA658 people · 20 mi SW
- Bryantown, MD359 people · 7 mi NW
- Benedict, MD68 people · 3 mi NE
- Eagle Harbor, MD67 people · 6 mi N
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 Mechanicsville's climate
What is the coldest month in Mechanicsville?
January, with a normal high of 44°F and a normal low of 25°F. The warmest is July (85°F by day, 66°F at night).
Does it snow in Mechanicsville?
Yes: 15 inches in a normal year, falling on 7 days with 0.1 inch or more, the most in February (6.2 inches).
What is the rainiest month in Mechanicsville?
September, with 4.87 in of precipitation in a normal year; the driest is February with 2.97 in.
What plant hardiness zone is Mechanicsville in?
The USDA's 2023 map puts Mechanicsville in zone 7b in ZIP code 20659, the nearest ZIP area. By the same method at Mechanicsville's NOAA station, the coldest night of a typical year reaches 6°F (29 years, 1991-2020): zone 7b.
How late can frost come in Mechanicsville?
In half of years the last 32°F night comes after April 17; in one year in ten it comes after May 2. Waiting until May 2 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Maryland climateThe statewide normals and every place in the state
- Solomons, MD19 miles from this station, 58.9°F a year
- Patuxent River Naval Air Station, MD21 miles from this station, 58.3°F a year
- Upper Marlboro, MD25 miles from this station, 56.0°F a year
- Oxon Hill, MD25 miles from this station, 57.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made