December weather forecast and Climate
Ascension Island, Saint Helena, Ascension and Tristan da Cunha SH

• The average high temperature in December: 29°C

Warmest months (with the highest average high temperature) are February, March, April and May (31°C).
Months with the lowest average high temperature are August, September, October and November (28°C).

• The average low temperature in December: 22°C

Months with the highest average low temperature are March, April and May (24°C).
Coldest months (with the lowest average low temperature) are July, August, September, October, November and December (22°C).

• The average humidity in December: 69%

The month with the highest relative humidity is January (70%).
The month with the lowest relative humidity is July (67%).

• The average rainfall in December: 4mm

The wettest month (with the highest rainfall) is April (33mm).
Driest months (with the lowest rainfall) are January, November and December (4mm).

• The average rainfall days in December: 1 days

The month with the highest number of rainy days is April (4 days).
Months with the lowest number of rainy days are November and December (1 days).

• The average sea temperature in December: 25°C

Best months for swimming (with the highest average sea temperature) are March, April and May (28°C).
Coldest months (with the lowest average sea temperature) are September and October (24°C).

• The average daylight in December: 13h

Months with the longest days are January and December (Average daylight: 13h).
Months with shortest days are February, March, April, May, June, July, August, September, October and November (Average daylight: 12h).

• The average sunshine in December: 6.4h

Months with most sunshine are March and April (Average sunshine: 8.9h).
The month with least sunshine is October (Average sunshine: 5.2h).

• The average UV index in December: 12

Months with the highest UV index are January, February, March, April, September, October, November and December (UV index 12).
Months with the lowest UV index are June and July (UV index 9).