World Resorts USA Block Island Weather

Block Island weather in December

Weather in Block Island: December

Average day temperature: 42.5°F
Average night temperature: 39.7°F
Sea water temperature: 49.9°F
Number of sunny days: 14 days
Day length: 9.2 - 9.4 hours
Number of rainy days: 2 days
Precipitation totals: 1.4 in.

Air temperature in December, °F

Show year:
2025
2024
2023

The highest day temperature during December of 2025 was 53°F. At the same time the lowest night temperature was 19°F. Daily and nightly averages during December were 38.4°F and 33.9°F.

Sea water temperature in Block Island in December, °F

Show year:
2025
2024
2023

The average sea water temperature in December of 2025 was 47.3°F. The highest and lowest sea temperatures during the month were 51.6°F and 43.5°F.

Sunny, partly cloudy and cloudy days

Mostly all days in December are sunny but cloudy days are also possible.

Precipitation total in December, in.

Precipitation total value in Block Island in December is 1.4 in. Other months of the year show relatively similar values.

Wind speed in December, mph

The average wind speed value in December is 16.1 mph It makes December most windy month of the year.

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in December is: 5.2.

Best time for vacation in Block Island

Sunniest months:
November 16 days
December 14 days
September 14 days
Warmest months:
July 74.4 °F
August 73.5 °F
September 68.8 °F
Warmest sea temp:
August 70.1 °F
July 68.6 °F
September 68.3 °F
Coldest months:
January 37.4 °F
February 37.4 °F
December 42.5 °F
Rainiest months:
October 4 days
January 3 days
March 3 days
Windiest months:
December 16.1 mph
November 15.7 mph
January 15.6 mph

Block Island on a weather map

Block Island
+48°F
N 20 mph
Feels like: +41°F
Precip.: 86%
Places in USA:
Name
°F
+54°F
+75°F
+75°F
+46°F
+55°F
+73°F
+73°F
+72°F
+48°F
+64°F
+54°F
+70°F
+73°F
+73°F
+37°F
24 Hours Forecast
Block Island
Local time: 20:53
January 09, friday
2100
48°F
N
20 mph
January 10, saturday
0000
46°F
NE
22 mph
0300
45°F
E
15 mph
0600
41°F
SE
12 mph
0900
41°F
S
8 mph
1200
41°F
W
8 mph
1500
41°F
W
13 mph
1800
41°F
W
18 mph
Units of measurement: °C / °F