Climate and monthly weather forecastDerby, CT
Climate and monthly weather forecast
The climate of Derby
Derby, Connecticut finds itself within the climatic parameters of the Köppen's Cfa climate classification. Its location, tucked away in the northeastern United States, provides it with a humid subtropical climate that sees no dry season.Throughout the year, the climate displays a melodrama of variations, with temperatures ebbing between 24.6°F (-4.1°C) and 81.9°F (27.7°C). The humidity plays a persistent role in Derby's climate, sticking to a rangefrom 72% to 77%. Pressure too takes a nearly mesmeric orbit around 30" (762mm), with minor deviations.
Rainfall, another prolific performer in this climate continues without respite. Derby receives rainfall every month, with the volume fluctuating from as low as 2.24" (57mm) to up to 4.06" (103mm). Alongside, ranging from 9.4 to 18, it experiences rainy days. The snowy days are significantly fewer in number compared to rainy days, with December seeing 4.6 snow days being the peak, and shovelling only up to 2.4" (61mm) of snow.
Unique among the weather patterns in Derby is the daylight duration, which peaks in June to 15.1 hours but dips as down to 9.2 hours in December. Additionally, the UV index oscillates between a low of 2 and a high of 6, with the increased levels evident from May to August.
The best time to visit Derby
For those favoring warm weather, the peak summer months of July and August promise the most appealing temperatures. The mercury typically scales up to about 80.2°F (26.8°C), the daylight lasts for nearly 14.8 hours, and the UV index stays as high as 6. This period is accompanied by manageable humidity levels around 75%.The worst time to visit Derby
Winter, particularly January and February, might prove challenging for some visitors, with temperatures diving as low as 24.6°F (-4.1°C). This period also observes increased average snowfall of up to 3.23" (82mm) and features fewer daylight hours, averaging a scant 10.6 hours in February.Spring weather in Derby
Spring in Derby progressively warms up, with temperatures ascending starting from 34.7°F (1.5°C) in March to a conducive 66.7°F (19.3°C) in May. Concurrently, the amount of daylight goes from 12 hours to approximately 14.5 hours. There is an uptick in rainfall from 2.91" (74mm) in March to 2.83" (72mm) in May, but snowfall winds down, finally reaching a standstill in May.Summer weather in Derby
Following spring, summer brings with it prime temperatures between 66.7°F (19.3°C) and 81.9°F (27.7°C) along with extensive daylight hours reaching up to 15.1 hours in June. It's a period of clear skies with sunshine hours ranging from 8.7 hours to 10.5 hours. However, an important note is the increased rainfall during this period, culminating in 3.43" (87mm) in July.Autumn weather in Derby
Autumn draws in with a comfortable range of temperatures from 61.7°F (16.5°C) to 73°F (22.8°C). Light begins to recede as daylight hours drop from 12.5 hours in September to 9.9 hours in November. Concurrently, rainfall reaches its peak at 3.5" (89mm) in October. A unique feature is the resumption of snowfall, albeit a small 0.35" (9mm) in November.Winter weather in Derby
Winters are characteristically cold with temperatures sinking to between 24.6°F (-4.1°C) and 40.3°F (4.6°C). Daylight is notably scarce - dipping to a meagre 9.2 hours in December. Rain gives way to snow, reaching a high of 2.4" (61mm) in December, marking the highest snowfall for the year.Weather in January
Derby, Connecticut starts off the year with January, a chilly month characterized by a daily high reaching to 34.7°F (1.5°C) and lows plummeting to 24.6°F (-4.1°C). Precipitation falls to a significant extent as snow, frosting the city in a beautiful winter wonderland as cloudy skies shroud the city in a constant cold embrace. Weather in January »Weather in February
With February, Derby sees a slight increase in temperature, however, it remains a chilly winter month. The presence of clouds appears to be persistent in February, slightly more than the previous month, creating a rather cold, overcast atmosphere. Weather in February »Weather in March
March in Derby, Connecticut is a harbinger of spring with temperatures rising to high of 44.2°F (6.8°C) and a low of 32°F (0°C). Despite the cool conditions, this month represents a weather transition from the cold, snowy days of January and February to a milder, spring-like feel. Weather in March »Weather in April
April brings significantly warmer weather to Derby, as winter recedes and gives way to spring blossoms. The days stretch longer now, carrying with them a sense of new beginnings and the promise of summer just around the corner. Residents of the city can expect frequent rains, prompting the growth of vibrant plant life that soon adorns the cityscape. Weather in April »Weather in May
As we move into May, the city of Derby, Connecticut transforms under clear, sunny skies and warm temperatures. Seasonal changes bring about a visible enhancement of the city's natural beauty. Regular showers continue to sustain the thriving flora, painting the city with hues of vibrant green. Weather in May »Weather in June
June in Derby brings about the arrival of summer with an average high temperature of 74.8°F (23.8°C) and a low of 59.5°F (15.3°C). Beautiful sunny days dominate the weather pattern, inviting locals and tourists alike to enjoy outdoor activities. Weather in June »Weather in July
July stands out as the warmest month in Derby, Connecticut with temperatures soaring to a high of 81.9°F (27.7°C) and a low of 66.7°F (19.3°C). Residents can look forward to longer days filled with sunshine and perfectly clear skies. Weather in July »Weather in August
August continues the summer trend with high temperatures, although marginally cooler than July. Cloud cover is infrequent, offering ample opportunities for activities under the summer sun. Light drizzles infuse the warm air with a refreshing change. Weather in August »Weather in September
September in Derby gifts the city with a gradual transition from summer heat to mild autumnal weather. The changing seasons bring picturesque foliage to the city, contributing to the scenic beauty. Random spurts of rain continue to fall, maintaining the city's moisture levels as the days start to shorten. Weather in September »Weather in October
With the onset of October, fall weather establishes its hold in Derby, Connecticut. The cityscape transforms with yellow, orange, and auburn hues, creating breathtaking landscapes. Periodic rainfall complements the cool temperatures, further enhancing the city's autumnal charm. Weather in October »Weather in November
November, the last month of the autumn in Derby, is also a frosty month, with an average temperature ranging between min 39.2°F (4°C) and max 49.8°F (9.9°C). The shift from October to November corresponds with a decrease in the average high-temperature, down to a chilly 49.8°F (9.9°C) from a comfortable 61.7°F (16.5°C). Weather in November »Weather in December
December brings the year in Derby to a close, wrapped in the cold embrace of winter. The city experiences its highest rainfall in this month, at 4.06" (103mm). Drops in temperatures turn the precipitation into snow, casting a pristine winter wonderland scenery. Weather in December »Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Derby's temperature records reveal January as the coldest month, marked by average highs of 34.7°F (1.5°C) and lows of 24.6°F (-4.1°C).
Throughout the year, there are 169.1 rainfall days, and 36.26" (921mm) of precipitation is accumulated.
Months with snowfall in Derby are January through April, November and December.
Throughout the year, there are 27.3 snowfall days, and 11.42" (290mm) of snow is accumulated.
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Derby.
The most humid month in Derby is February, with an average relative humidity of 77%.
The month with the most snowfall is February, when snow falls for 7.8 days and typically aggregates up to 3.23" (82mm) of snow.
With an average of 4.7h of sunshine, February has the least sunshine of the year.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Derby, Connecticut, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.
April is the least humid month, with an average relative humidity of 72%.
May through October are months without snowfall.
With an average of 15h and 6min of daylight, June has the longest days of the year.
The months with the highest UV index are June through August, with an average maximum UV index of 6.
July stands out as Derby's warmest month, with temperatures ranging between an average high of 81.9°F (27.7°C) and a low of 66.7°F (19.3°C).
July and August, with an average of 10.5h of sunshine, are months with the most sunshine.
September is the month with the least rainfall in Derby. Rain falls for 13.1 days and accumulates 2.24" (57mm) of precipitation.
The month with the most rainfall is December, when the rain falls for 12.8 days and typically aggregates up to 4.06" (103mm) of precipitation.
With an average of 9h and 18min of daylight, December has the shortest days of the year.
Average temperature
Derby, CT
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (34.7°F).
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (24.6°F).
Average pressure
Derby, CT
- Average pressure in January:
30.04"Hg - Average pressure in February:
30.02"Hg - Average pressure in March:
30.05"Hg - Average pressure in April:
29.98"Hg - Average pressure in May:
30.01"Hg - Average pressure in June:
29.93"Hg
- Average pressure in July:
29.95"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.05"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.09"Hg - Average pressure in December:
30.06"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed
Derby, CT
- Average wind speed in January:
9.6mph - Average wind speed in February:
9.3mph - Average wind speed in March:
9.3mph - Average wind speed in April:
8.7mph - Average wind speed in May:
7.2mph - Average wind speed in June:
6.6mph
- Average wind speed in July:
6.2mph - Average wind speed in August:
6.2mph - Average wind speed in September:
7mph - Average wind speed in October:
8.4mph - Average wind speed in November:
8.9mph - Average wind speed in December:
9.3mph
The windiest month (with the highest average wind speed) is January (9.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).
Average humidity
Derby, CT
The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is April (72%).
Average rainfall
Derby, CT
- Average rainfall in January:
2.48" - Average rainfall in February:
2.56" - Average rainfall in March:
2.91" - Average rainfall in April:
3.11" - Average rainfall in May:
2.83" - Average rainfall in June:
3.07"
- Average rainfall in July:
3.43" - Average rainfall in August:
3.03" - Average rainfall in September:
2.24" - Average rainfall in October:
3.5" - Average rainfall in November:
3.03" - Average rainfall in December:
4.06"
The wettest month (with the highest rainfall) is December (4.06").
The driest month (with the least rainfall) is September (2.24").
Average rainfall days
Derby, CT
- Average rainfall days in January:
9.4 days - Average rainfall days in February:
10.3 days - Average rainfall days in March:
13.7 days - Average rainfall days in April:
15.3 days - Average rainfall days in May:
17.2 days - Average rainfall days in June:
17.5 days
- Average rainfall days in July:
18 days - Average rainfall days in August:
16.8 days - Average rainfall days in September:
13.1 days - Average rainfall days in October:
14.8 days - Average rainfall days in November:
10.2 days - Average rainfall days in December:
12.8 days
The month with the highest number of rainy days is July (18 days).
The month with the least rainy days is January (9.4 days).
Average snowfall
Derby, CT
The month with the highest snowfall is February (3.23").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Derby, CT
- Average snowfall days in January:
7.5 days - Average snowfall days in February:
7.8 days - Average snowfall days in March:
5.5 days - Average snowfall days in April:
0.7 days - Average snowfall days in May:
0.2 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:
1 days - Average snowfall days in December:
4.6 days
The month with the highest number of snowfall days is February (7.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight / Average sunshine
Derby, CT
- Average daylight in January:
9h and 36min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 30min - Average daylight in June:
15h and 6min
- Average daylight in July:
14h and 48min - Average daylight in August:
13h and 48min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 6min - Average daylight in November:
9h and 54min - Average daylight in December:
9h and 18min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in January:
5h and 6min - Average sunshine in February:
4h and 42min - Average sunshine in March:
6h and 24min - Average sunshine in April:
8h and 24min - Average sunshine in May:
8h and 42min - Average sunshine in June:
9h and 36min
- Average sunshine in July:
10h and 30min - Average sunshine in August:
10h and 30min - Average sunshine in September:
8h and 54min - Average sunshine in October:
5h and 54min - Average sunshine in November:
5h and 36min - Average sunshine in December:
4h and 54min
The months with the most sunshine are July and August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days
Derby, CT
- Average sunshine days in January:
16.8 days - Average sunshine days in February:
12.3 days - Average sunshine days in March:
13.4 days - Average sunshine days in April:
12.3 days - Average sunshine days in May:
11.8 days - Average sunshine days in June:
10.3 days
- Average sunshine days in July:
11.5 days - Average sunshine days in August:
11.4 days - Average sunshine days in September:
14.4 days - Average sunshine days in October:
14.7 days - Average sunshine days in November:
17.5 days - Average sunshine days in December:
14.5 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is June (10.3 days).
Average UV index
Derby, CT
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover
Derby, CT
The months with the most cloud cover are February and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility
Derby, CT
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
