Adelphi, United States — Weather in December 2026

Monthly climate averages for Adelphi, United States. Based on 10-year ERA5 reanalysis data.

Cfa Humid Subtropical
2.5 /10
Poor

December is a poor month in Adelphi

Climate Overview

Adelphi, United States in December has cold conditions, with highs averaging around 8.3°C (47°F).

This month falls at the beginning of Winter. Cold conditions dominate the month.

Temperatures remain fairly steady throughout December, with daily highs around 9°C (48°F).

Rainfall is heaviest during the middle of the month, while the first third tends to be drier.

Expect around 6.3h of sunshine at the start of December, decreasing to 5.6h by the end.

The warmest days tend to fall around the 1th, averaging 10°C (50°F).

Compared to November, this month is about 5°C cooler with 1 more rainy days. Temperatures begin dropping heading into January.

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Monthly December Averages

Temperature
8°C / 1°C
Feels Like
5°C / -3°C
Rain
9 days · 98 mm
Sunshine
5.9h / day
Humidity
70% — Humid
Wind
16 km/h
Wind Direction
W (275°)
Gusts
37 km/h
Daylight
9.5 h
Cloud Cover
60%
Clear Sky Days
3.9
UV Index
2.3 — Moderate
Dew Point
0°C — Dry
Moon Phase
Waxing Crescent · 31%
Snow Days
2 days · 2.8 cm
Frost Days
14 days

Climate Charts

Daily averages based on historical data (2016–2025)

Daily Temperature

16°C 12°C 8°C 4°C 0°C -4°C -8°C 151015202531
HighLow

Daily Precipitation

0 mm 2 mm 4 mm 6 mm 8 mm 151015202531
Rainfall

Daily Sunshine

0h 2h 4h 6h 8h 10h 151015202531
Sunshine

Daily Wind Speed

0 5 10 15 20 25 151015202531
Wind Speed
Sun Position
Sunrise 07:21
Daylight 9.4h
Sunset 16:48

What to Expect

Cold daytime highs of 8°C (47°F) mean shorter outdoor excursions with warming breaks.

Rain usually comes in shorter passing showers rather than all-day rain.

2 of the last 5 yearly records were warmer than this month's long-run average.

Compare Months

January
Poor
Temp
6°C / -1°C
Feels Like
3°C / -6°C
Rain
10days (84 mm) Wet
Sun
6.2h Fair
Humidity
68% Muggy
UV
2.6 Moderate
Snow Days
4days
View Details
February
Poor
Temp
10°C / 1°C
Feels Like
6°C / -3°C
Rain
10days (88 mm) Wet
Sun
6.7h Fair
Humidity
67% Muggy
UV
3.5 Moderate
Snow Days
4days
View Details
March
Fair
Temp
14°C / 4°C
Feels Like
11°C / 0°C
Rain
10days (84 mm) Wet
Sun
8.2h Good
Humidity
64% Muggy
UV
5 Moderate
Snow Days
2days
View Details
April best
Good
Temp
19°C / 9°C
Feels Like
18°C / 6°C
Rain
9days (84 mm) Wet
Sun
9.1h Good
Humidity
65% Muggy
UV
5.8 High
View Details
May best
Excellent
Temp
23°C / 14°C
Feels Like
24°C / 13°C
Rain
13days (118 mm) Wet
Sun
9.3h Good
Humidity
73% Muggy
UV
6.5 High
View Details
June best
Excellent
Temp
29°C / 19°C
Feels Like
31°C / 20°C
Rain
11days (112 mm) Wet
Sun
11.4h Excellent
Humidity
69% Muggy
UV
7.4 Very High
View Details
July
Fair
Temp
31°C / 22°C
Feels Like
35°C / 25°C
Rain
14days (152 mm) Wet
Sun
11.8h Excellent
Humidity
72% Muggy
UV
7.6 Very High
View Details
August
Good
Temp
29°C / 21°C
Feels Like
33°C / 23°C
Rain
12days (104 mm) Wet
Sun
10.6h Excellent
Humidity
74% Muggy
UV
6.8 High
View Details
September best
Excellent
Temp
26°C / 18°C
Feels Like
28°C / 19°C
Rain
11days (97 mm) Wet
Sun
8.6h Good
Humidity
74% Muggy
UV
5.2 High
View Details
October best
Excellent
Temp
21°C / 12°C
Feels Like
20°C / 11°C
Rain
8days (78 mm) Wet
Sun
7.9h Good
Humidity
72% Muggy
UV
4.5 Moderate
View Details
November
Fair
Temp
14°C / 5°C
Feels Like
11°C / 2°C
Rain
8days (70 mm) Wet
Sun
7.2h Good
Humidity
68% Muggy
UV
3.1 Moderate
Snow Days
1days
View Details
December
Poor
Temp
8°C / 1°C
Feels Like
5°C / -3°C
Rain
9days (98 mm) Wet
Sun
5.9h Fair
Humidity
70% Muggy
UV
2.3 Moderate
Snow Days
2days
View Details
Month Temp Feels Like Rain Sun Humidity UV Status
January 6°C / -1°C 3°C / -6°C 10days (84 mm) Wet 6.2h Fair 68% Muggy 2.6 Moderate Poor View Details
February 10°C / 1°C 6°C / -3°C 10days (88 mm) Wet 6.7h Fair 67% Muggy 3.5 Moderate Poor View Details
March 14°C / 4°C 11°C / 0°C 10days (84 mm) Wet 8.2h Good 64% Muggy 5 Moderate Fair View Details
April best 19°C / 9°C 18°C / 6°C 9days (84 mm) Wet 9.1h Good 65% Muggy 5.8 High Good View Details
May best 23°C / 14°C 24°C / 13°C 13days (118 mm) Wet 9.3h Good 73% Muggy 6.5 High Excellent View Details
June best 29°C / 19°C 31°C / 20°C 11days (112 mm) Wet 11.4h Excellent 69% Muggy 7.4 Very High Excellent View Details
July 31°C / 22°C 35°C / 25°C 14days (152 mm) Wet 11.8h Excellent 72% Muggy 7.6 Very High Fair View Details
August 29°C / 21°C 33°C / 23°C 12days (104 mm) Wet 10.6h Excellent 74% Muggy 6.8 High Good View Details
September best 26°C / 18°C 28°C / 19°C 11days (97 mm) Wet 8.6h Good 74% Muggy 5.2 High Excellent View Details
October best 21°C / 12°C 20°C / 11°C 8days (78 mm) Wet 7.9h Good 72% Muggy 4.5 Moderate Excellent View Details
November 14°C / 5°C 11°C / 2°C 8days (70 mm) Wet 7.2h Good 68% Muggy 3.1 Moderate Fair View Details
December 8°C / 1°C 5°C / -3°C 9days (98 mm) Wet 5.9h Fair 70% Muggy 2.3 Moderate Poor View Details

What to Wear

Full winter gear is a must — insulated coat, thermal base layers, warm hat, gloves, and waterproof boots.

A waterproof jacket or compact umbrella is recommended for occasional showers.

Packing List

Warm coatUmbrellaComfortable walking shoes

Frequently Asked Questions

December is typically poor for visiting Adelphi, with average highs of 8°C (47°F) and around 9 rainy days. Adelphi, United States in December has cold conditions, with highs averaging around 8.3°C (47°F).
Adelphi typically sees around 9 rainy days in December with 98 mm (3.9 in) of total rainfall. An umbrella should suffice.
Yes, nights in Adelphi during December are cold, averaging 1°C (33°F). Pack warm layers and a coat for evenings.
With highs of 8°C (47°F) and lows of 1°C (33°F) in December, we recommend: Warm coat, Umbrella, Comfortable walking shoes. Comfortable walking shoes are essential.
December is not the most favourable month weather-wise in Adelphi. Consider visiting during months with milder temperatures or less rainfall for a better experience.
The average UV index in Adelphi during December is 2 (low). No special sun protection is needed.
Adelphi gets approximately 10 hours of daylight per day in December, with around 6 hours of sunshine.
Yes, Adelphi typically sees around 2 snow days in December with roughly 3 cm (1 in) of snowfall.

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