Climate and monthly weather forecastRockville, MD
Climate and monthly weather forecast
The climate of Rockville
Rockville, located in Maryland, USA, has a predominating Köppen climate classification of Cfa, indicating a humid subtropical state where there is no dry season. A comprehensive study of the climatological parameters reveals some fascinating patterns and fluctuations throughout the year.Across the year, daytime temperatures demonstrate considerable variability, ranging from a low average of 39°F (3.9°C) in January to a peak average of 87.1°F (30.6°C) in July. Night time temperatures also reflect this trend, recording a minimum average of 26.2°F (-3.2°C) in January and a maximum of 68.5°F (20.3°C) in July. Consequently, a broad temperature range characterizes Rockville's climate, indicative of the transition from quite chilly winters to balmy summers.
Humidity index also fluctuates throughout the year, with values averaging between 70% in July and 77% in December. Rainfall trends are somewhat steady with minor ups and downs across the months, with the record rainfall of around 3.9" (99mm) occurring in August. Although snowfall is minimal and mainly concentrated in the first quarter of the year with the highest average of around 3.03" (77mm) in March.
The city's daylight hours wax and wane according to the calendar months, with the shortest average daylight of 9.8 hours in December and the longest of 14.9 hours in June. The average hours of sunshine follow this pattern, ranging from 5.1 hours in January to 10.8 hours in July.
The best time to visit Rockville
Given the city's varying climatological parameters, the best time for a visit to Rockville would arguably be from May to September. During this period, daytime temperatures remain comfortably within the 64.4°F (18°C) to 87.1°F (30.6°C) range, while the nights mostly stay above 55.4°F (13°C) offering both warm days and agreeably mild nights. Moreover, visitors can enjoy the longest daylight hours with average sunshine duration extending from 8.9 hours in May to a generous 10.8 hours in July.The worst time to visit Rockville
Given its climatic conditions, the least favorable period for visiting Rockville would be the winter months, particularly from December to February. During this period, temperatures can drop to a chilly average low of 26.2°F (-3.2°C) in January, and snowfall, although minimal, peaks in January with an average of 2.6" (66mm).Spring weather in Rockville
Spring in Rockville features a gradual increase in temperature; in March, the daytime average stands at 52°F (11.1°C), which leaps to 64.4°F (18°C) in April and 73.9°F (23.3°C) in May. The night time temperatures also rise in step, from an average of 36.1°F (2.3°C) in March to 55.4°F (13°C) in May. The season is marked by increasing day lengths, crescendoing to an average of 14.3 hours of daylight and 8.9 hours of sunshine by May.Summer weather in Rockville
The summer season in Rockville showcases the year's highest temperatures, with July's averages ruling at 87.1°F (30.6°C) during the day and 68.5°F (20.3°C) at night. On the brighter side, the region enjoys extended daylight hours that last from 14.6 hours in July to 13.7 hours in August, coupled with high amounts of sunshine, peaking at 10.8 hours in July.Autumn weather in Rockville
Autumn in Rockville witnesses a gradual decrease in temperatures, sinking from 77.9°F (25.5°C) in September to 53.4°F (11.9°C) by November during the daytime, and from 60.8°F (16°C) to 38.5°F (3.6°C) during the night. The daylight hours also retreat, with average daylight decreasing from 12.4 hours in September to 10 hours by November.Winter weather in Rockville
Winter announces itself in Rockville with a sharp plunge in temperatures, the daytime average reaches a low of 39°F (3.9°C) in January and the nighttime average dips to 26.2°F (-3.2°C). Although the city experiences some snowfall during this season, the volume is modest. Daylight hours are the shortest in the year averaging 9.5 hours in December, with sunshine duration equally reduced to 5.1 hours. This season is indeed the coldest and least sunlit period in Rockville.Weather in January
Grounded firmly in the heart of winter, Rockville, Maryland experiences chilly conditions throughout January. Nestled between the milder December and the slightly warmer February, daytime temperatures may rise up to 39°F (3.9°C), while at night they can plunge to as low as 26.2°F (-3.2°C). Weather in January »Weather in February
February arrives with a subtle shift. There's a slight increase in average temperatures compared to January, reaching 43.9°F (6.6°C) at the highest and dipping to 28.6°F (-1.9°C) at the lowest. This time of the year paints images of melting snow and icicles, preparing to welcome spring. Weather in February »Weather in March
There's a significant change in Rockville's climate by March. Temperatures range from 52°F (11.1°C) at a high to 36.1°F (2.3°C) at a low, signaling the approach of spring. The weather becomes increasingly dynamic, with alterations between bright, sunny days and significant rainfall. Weather in March »Weather in April
April, representing spring in its full form, embraces Rockville with a mix of consistent rainfall and warm weather. The temperatures normally range from a maximum of 64.4°F (18°C) to a minimum of 45.9°F (7.7°C), showcasing a marked increase from March. Weather in April »Weather in May
May turns a new leaf in Rockville, Maryland, as it marks the transition from spring to summer. The weather revolves around the spectrum of warm to hot, with temperature readings setting between 73.9°F (23.3°C) at the top end and 55.4°F (13°C) at the bottom. Weather in May »Weather in June
The pinnacle of summer in Rockville, June showcases a rise in temperatures, peaking at 82°F (27.8°C) and settling at 63.7°F (17.6°C). Notably, the length of daylight peaks at nearly 15 hours, maximizing opportunities for summer activities. Weather in June »Weather in July
July in Rockville offers the warmest climate of the year, with temperatures soaring to an apex of 87.1°F (30.6°C) and falling to a relatively warmer 68.5°F (20.3°C). While rainfall is common, it doesn’t take away from sunshine hours, which hover around the maximum amounts experienced in June. Weather in July »Weather in August
August retains the traits of Rockville's warm summer, though with temperatures slightly falling from the July highs to a range of 85.3°F (29.6°C) and 67.5°F (19.7°C). This month transitions the switch from summer to autumn, impacting the city's weather. Weather in August »Weather in September
September in Rockville witnesses a significant drop in temperatures from August, going from a high of 77.9°F (25.5°C) to a low of 60.8°F (16°C). The onset of autumn is apparent, with conditions starting to lean towards the cooler side. Weather in September »Weather in October
October stands as a distinctive marker of the fall season in Rockville, Maryland. Temperatures during this time stay between the highs of 65.5°F (18.6°C) and the lows of 49.8°F (9.9°C), reflecting the cooling trend from September. Weather in October »Weather in November
The penultimate month, November, brings Rockville one step closer to winter. The town experiences a further decline in temperatures, with highs of 53.4°F (11.9°C) and lows of 38.5°F (3.6°C). Rainfall sees a slight drop as the city gears up for the prospect of snow dominating the scene in the following month. Weather in November »Weather in December
Immersed in the spirit of the holiday season, December in Rockville plunges into the heart of winter with temperatures oscillating between a high of 45.3°F (7.4°C) and a low of 32.9°F (0.5°C). The chance of snowfall begins to escalate, casting a festive white blanket over the city. Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Rockville, MD
The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (39°F).
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure
Rockville, MD
- Average pressure in January:
30.11"Hg - Average pressure in February:
30.07"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.99"Hg - Average pressure in May:
30.01"Hg - Average pressure in June:
29.95"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.99"Hg - Average pressure in September:
30.05"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.14"Hg - Average pressure in December:
30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed
Rockville, MD
- Average wind speed in January:
7.6mph - Average wind speed in February:
7.8mph - Average wind speed in March:
8mph - Average wind speed in April:
7.8mph - Average wind speed in May:
6.4mph - Average wind speed in June:
5.8mph
- Average wind speed in July:
5.1mph - Average wind speed in August:
5mph - Average wind speed in September:
5.6mph - Average wind speed in October:
6.5mph - Average wind speed in November:
6.9mph - Average wind speed in December:
7mph
The windiest month (with the highest average wind speed) is March (8mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity
Rockville, MD
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is July (70%).
Average rainfall
Rockville, MD
- Average rainfall in January:
1.97" - Average rainfall in February:
2.01" - Average rainfall in March:
2.32" - Average rainfall in April:
2.56" - Average rainfall in May:
3.03" - Average rainfall in June:
2.48"
The wettest month (with the highest rainfall) is August (3.9").
The driest month (with the least rainfall) is January (1.97").
Average rainfall days
Rockville, MD
- Average rainfall days in January:
9.6 days - Average rainfall days in February:
9.6 days - Average rainfall days in March:
12.8 days - Average rainfall days in April:
14.4 days - Average rainfall days in May:
17.1 days - Average rainfall days in June:
15.9 days
- Average rainfall days in July:
16.6 days - Average rainfall days in August:
15.9 days - Average rainfall days in September:
13.7 days - Average rainfall days in October:
11.7 days - Average rainfall days in November:
9.2 days - Average rainfall days in December:
9.9 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is November (9.2 days).
Average snowfall
Rockville, MD
The month with the highest snowfall is March (3.03").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Rockville, MD
- Average snowfall days in January:
5.3 days - Average snowfall days in February:
5.3 days - Average snowfall days in March:
3.2 days - Average snowfall days in April:
0.2 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0.5 days - Average snowfall days in December:
3.2 days
The months with the highest number of snowfall days are January and February (5.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Rockville, MD
- Average daylight in January:
9h and 48min - Average daylight in February:
10h and 48min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 18min - Average daylight in June:
14h and 54min
- Average daylight in July:
14h and 36min - Average daylight in August:
13h and 42min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 12min - Average daylight in November:
10h and 6min - Average daylight in December:
9h and 30min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in January:
5h and 6min - Average sunshine in February:
5h and 6min - Average sunshine in March:
6h and 48min - Average sunshine in April:
8h and 54min - Average sunshine in May:
8h and 54min - Average sunshine in June:
10h and 12min
- Average sunshine in July:
10h and 48min - Average sunshine in August:
10h and 18min - Average sunshine in September:
9h and 0min - Average sunshine in October:
5h and 36min - Average sunshine in November:
5h and 48min - Average sunshine in December:
5h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 6min).
Average sunshine days
Rockville, MD
- Average sunshine days in January:
17.6 days - Average sunshine days in February:
15.1 days - Average sunshine days in March:
14.8 days - Average sunshine days in April:
13.9 days - Average sunshine days in May:
12.1 days - Average sunshine days in June:
12.4 days
- Average sunshine days in July:
12 days - Average sunshine days in August:
12.8 days - Average sunshine days in September:
14.9 days - Average sunshine days in October:
17.1 days - Average sunshine days in November:
19.4 days - Average sunshine days in December:
17.7 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is July (12 days).
Average UV index
Rockville, MD
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover
Rockville, MD
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility
Rockville, MD
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).





