Climate and monthly weather forecastChatham, MA
Climate and monthly weather forecast
The climate of Chatham
Predominantly falling under the Köppen climate classification of Cfa, the town of Chatham, Massachusetts, experiences a humid subtropical climate with no dry season. Geographically, the town is situated along the southeastern tip of Cape Cod and is therefore influenced notably by the Atlantic Ocean. The coastal climate manifests in the form of a comfortable year-round weather, frequent rainfall, and the absence of extremely high temperatures.Throughout the year, Chatham is subjected to a range of temperatures and variations in its climatic pattern. The highest average monthly temperature reaches a maximum of 71.6°F (22°C) in the month of July, while the lowest plummets down to 31.6°F (-0.2°C) in January. Humidity levels remain fairly constant, hovering around the 74% to 85% range. The coastal town records noticeable rainfall every month, with October being the month with the highest rainfall 2.83" (72mm), contrasting with February, which records the least rainfall at 1.57" (40mm).
Snowfall, while not frequent, does occur in Chatham, specifically from January to March, and also in November. The town witnesses its maximum snowfall of 1.38" (35mm) in February. Additionally, wind speeds vary across the year with January and December experiencing the maximum average wind speed of 18mph (29km/h) and the minimum speed of 11.4mph (18.3km/h) is measured in August.
The best time to visit Chatham
Given the subtropical nature of its climate, the best time to visit Chatham is typically during the summer months from June to August. During this period, the average temperatures hover between 63°F (17.2°C) to 71.6°F (22°C) and the daylight hours extend up to 14.8 hours in a day, ensuring pleasurable weather for outdoor activities. Also, the lessened probability of rainfall during these months compared to other parts of the year, make it ideal for various recreational activities.The worst time to visit Chatham
The period from December to February could be considered less popular for visits due to the low temperatures that range from 31.6°F (-0.2°C) to 41°F (5°C) and reduced daylight hours at 9.2 to 10.6 hours a day. These factors may restrict outdoor activities. Additionally, Chatham records its peak snowfall in inches during these months which might deter travelers seeking a milder climate.Spring weather in Chatham
Springtime from March through May in Chatham is characterized by a moderate rise in temperatures that range between 39°F (3.9°C) to 54.3°F (12.4°C). Rainfall tends to increase as the season progresses, with May recording 1.81" (46mm) of rain. Though snow recedes after March, the weather remains cautiously cool, ideal for visitors appreciating a still-cool but gradually warming atmosphere.Summer weather in Chatham
Summer months from June to August offer the most inviting weather for visitors to Chatham. During this period, average monthly high temperatures range from 63°F (17.2°C) to 71.6°F (22°C). This season also sees the longest daylight hours, extending up to 15.2 hours, along with bright sunshine ranging from 9.4 to 10.7 hours a day. Showers are also less frequent during the summer months, making this season perfect for outdoor activities.Autumn weather in Chatham
Autumn in the span of September to November brings a slight drop in temperatures with an average range between 59.5°F (15.3°C) to 66.6°F (19.2°C). The average daylight hours start to decrease but remain ample, falling between 9.8 to 12.5 hours a day. Despite the lower temperature and daylight, this season is characterized by its color changing foliage, offering a beautiful landscape for visitors.Winter weather in Chatham
The winter months from December through to February are marked by the lowest average temperatures, falling between 31.6°F (-0.2°C) to 41°F (5°C). Chatham observes its lowest daylight hours, hovering between 9.2 to 10.6 hours a day during these winter months. The chances of snow are also significant during this season, offering a very different landscape for visitors keen on experiencing a coastal winter.Weather in January
Chatham, Massachusetts, in January experiences cold conditions with the highest temperature rising to 39°F (3.9°C) and lowest falling to 31.6°F (-0.2°C). Snow is a common spectacle during this month, with snowfall days recorded typically being around six. Weather in January »Weather in February
In Chatham, the month of February is akin to its predecessor, falling under the grasp of winter's coldness. This month, Chatham sees a minor rise in temperature from January, with the lowest temperature recorded at 32°F (0°C). Weather in February »Weather in March
March is yet another transition month in Chatham, with a shift from the peak of winter towards the initial whispers of spring. The environment becomes warmer, as the highest monthly temperature subtly climbs to 41°F (5°C). This month is marked by considerable rainfall, making it one of the rainiest periods of the year with 1.85" (47mm) of rainfall. Weather in March »Weather in April
April in Chatham witnesses the onset of a wonderful spring season, with temperatures ascending, averaging approximately 46.9°F (8.3°C) as the monthly high. This month distinguishes itself from the comparatively rainier season of March, with a marginal increase in rainfall to 2.05" (52mm). Weather in April »Weather in May
May in Chatham is a delightful month, as it transitions towards the eagerly awaited summer season. The highest point of temperature climbs to an average of 54.3°F (12.4°C), boosting the bloom of local flora and fauna. This month also signifies a slight decrease in rainfall than April, marking a shift from the showery spring to a much drier summer. Weather in May »Weather in June
Chatham's June weather marks the onset of summer, characterized by warm temperatures and extended daylight hours. The temperature moves towards a balmy 63°F (17.2°C) as the highest average in the month underscoring the arrival of summer. Weather in June »Weather in July
Chatham's weather in July is distinctively summery, with July standing as the hottest month of the year. The month's peak temperature emerges as 70.3°F (21.3°C), making it an ideal period for beach-goers and outdoor enthusiasts. Weather in July »Weather in August
August in Chatham continues the summer trend set by July, with high temperatures and dry, sunny days. Temperatures range from a high of 71.6°F (22°C), the month's biggest temperature average. August is also characterized by a slight decrease in UV index from July, signaling shorter daylight hours as fall gradually starts to set in. Weather in August »Weather in September
September in Chatham represents the transition from the hot summer season to the cooler autumn months. The temperature begins to drop, with the month's maximum temperature averaging at a cooler 66.6°F (19.2°C). September stands out with its increase in rainfall to 1.85" (47mm), reflecting the shift into the autumn season. Weather in September »Weather in October
October in Chatham is emblematic of the full arrival of autumn, characterized by falling temperatures and vibrant fall colors. Although temperatures drop down from September, weather in October stays rather comfortable with 59.5°F (15.3°C) as the highest average. Weather in October »Weather in November
The eleventh month, November, in Chatham is marked by a distinct chill in the air, signaling the onset of the cold season. Temperatures take a deeper dive, with the highest average monthly temperature dropping to 51.3°F (10.7°C). Weather in November »Weather in December
Chatham's December concludes the year with the advent of winter. In this last month, temperatures plunge further with the highest average at 44.4°F (6.9°C), spelling out the arrival of the winter snowfall. The first flakes of snow begin to fall in December with an average snowfall of 0.67" (17mm) recorded for the month. Weather in December »Updated: Aug 14, 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
January and February are identified as the coldest months, with an average high-temperature of 39°F (3.9°C).
Throughout the year, there are 142.4 rainfall days, and 22.09" (561mm) of precipitation is accumulated.
January through April, November and December are months with snowfall.
In Chatham, during the entire year, snow falls for 20.8 days and aggregates up to 4.37" (111mm) of snow.
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
February is the month with the most snowfall. Snow falls for 5 days and accumulates 1.38" (35mm) of snow.
The month with the coldest seawater is March, with an average ocean temperature of 39.9°F (4.4°C).
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, 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.
In Chatham, snow does not fall in May through October.
The months with the highest humidity are June and July, with an average relative humidity of 85%.
With an average of 15h and 12min of daylight, June has the longest days of the year.
July and August, with an average maximum UV index of 6, are months with the highest UV index.
August brings the highest temperatures in Chatham, with an average high of 71.6°F (22°C) and an average low of 68.2°F (20.1°C).
The month with the warmest seawater is August, with an average ocean temperature of 67.6°F (19.8°C).
The month with the most sunshine is August, with an average of 10.7h of sunshine.
The month with the most rainfall is October, when the rain falls for 13.4 days and typically aggregates up to 2.83" (72mm) of precipitation.
With an average relative humidity of 74%, November is the least humid month.
The month with the least rainfall is November, when the rain falls for 11.5 days and typically collects 1.46" (37mm) of precipitation.
December has the shortest days of the year, with an average of 9h and 12min of daylight.
The month with the least sunshine in Chatham is December, with an average of 4.3h of sunshine.
Average temperature
Chatham, MA
The warmest month (with the highest average high temperature) is August (71.6°F).
The months with the lowest average high temperature are January and February (39°F).
The month with the highest average low temperature is August (68.2°F).
The coldest month (with the lowest average low temperature) is January (31.6°F).
Average pressure
Chatham, MA
- Average pressure in January:
29.99"Hg - Average pressure in February:
29.98"Hg - Average pressure in March:
30.02"Hg - Average pressure in April:
29.98"Hg - Average pressure in May:
30.02"Hg - Average pressure in June:
29.93"Hg
- Average pressure in July:
29.96"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:
30.06"Hg - Average pressure in December:
30.02"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed
Chatham, MA
- Average wind speed in January:
18mph - Average wind speed in February:
17.5mph - Average wind speed in March:
17.6mph - Average wind speed in April:
15.2mph - Average wind speed in May:
13.2mph - Average wind speed in June:
12.4mph
- Average wind speed in July:
11.6mph - Average wind speed in August:
11.4mph - Average wind speed in September:
13.5mph - Average wind speed in October:
15.5mph - Average wind speed in November:
16.9mph - Average wind speed in December:
17.5mph
The windiest month (with the highest average wind speed) is January (18mph).
The calmest month (with the lowest average wind speed) is August (11.4mph).
Average humidity
Chatham, MA
The months with the highest relative humidity are June and July (85%).
The month with the lowest relative humidity is November (74%).
Average rainfall
Chatham, MA
- Average rainfall in January:
1.69" - Average rainfall in February:
1.57" - Average rainfall in March:
1.85" - Average rainfall in April:
2.05" - Average rainfall in May:
1.81" - Average rainfall in June:
1.69"
- Average rainfall in July:
1.73" - Average rainfall in August:
1.5" - Average rainfall in September:
1.85" - Average rainfall in October:
2.83" - Average rainfall in November:
1.46" - Average rainfall in December:
2.05"
The wettest month (with the highest rainfall) is October (2.83").
The driest month (with the least rainfall) is November (1.46").
Average rainfall days
Chatham, MA
- Average rainfall days in January:
9.5 days - Average rainfall days in February:
8.3 days - Average rainfall days in March:
10.8 days - Average rainfall days in April:
13.1 days - Average rainfall days in May:
14.6 days - Average rainfall days in June:
13.4 days
- Average rainfall days in July:
13.8 days - Average rainfall days in August:
12.1 days - Average rainfall days in September:
10.7 days - Average rainfall days in October:
13.4 days - Average rainfall days in November:
11.5 days - Average rainfall days in December:
11.2 days
The month with the highest number of rainy days is May (14.6 days).
The month with the least rainy days is February (8.3 days).
Average snowfall
Chatham, MA
The month with the highest snowfall is February (1.38").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Chatham, MA
- Average snowfall days in January:
6 days - Average snowfall days in February:
5 days - Average snowfall days in March:
3.7 days - Average snowfall days in April:
0.8 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:
0.6 days - Average snowfall days in December:
4.7 days
The month with the highest number of snowfall days is January (6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature
Chatham, MA
The best month for swimming (with the highest average sea temperature) is August (67.6°F).
The coldest month (with the lowest average sea temperature) is March (39.8°F).
Average daylight / Average sunshine
Chatham, MA
- 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 36min - Average daylight in June:
15h and 12min
- 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 48min - Average daylight in December:
9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in January:
4h and 30min - Average sunshine in February:
4h and 30min - Average sunshine in March:
5h and 48min - Average sunshine in April:
8h and 18min - Average sunshine in May:
8h and 24min - Average sunshine in June:
9h and 24min
- Average sunshine in July:
10h and 30min - Average sunshine in August:
10h and 42min - Average sunshine in September:
8h and 30min - Average sunshine in October:
6h and 36min - Average sunshine in November:
5h and 12min - Average sunshine in December:
4h and 18min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).
Average sunshine days
Chatham, MA
- Average sunshine days in January:
13 days - Average sunshine days in February:
13.2 days - Average sunshine days in March:
13.9 days - Average sunshine days in April:
14.5 days - Average sunshine days in May:
14.8 days - Average sunshine days in June:
15.7 days
- Average sunshine days in July:
16.4 days - Average sunshine days in August:
17.6 days - Average sunshine days in September:
16.9 days - Average sunshine days in October:
15.5 days - Average sunshine days in November:
14.9 days - Average sunshine days in December:
13.6 days
The month with the most sunshine days is August (17.6 days).
The month with the least sunshine days is January (13 days).
Average UV index
Chatham, MA
The months with the highest UV index are 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
Chatham, MA
The month with the most cloud cover is December (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility
Chatham, MA
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).
