Humidity Type:
Difference?

Detailed Dew Point Data

Current
Measure Value
Dew Point 15.2 °C
Dew Pt Trend -0.3 °C /hr
24hr Mean Dew Pt 17.2 °C
Wet-Bulb Temperature 16.9 °C
Absolute Humidity 12.89 gm-3
Air Density 1209.37 gm-3
Recent Averages and Extremes
Measure Today Yesterday
Minimum 15.2 °C
02:44
14.8 °C
17:54
Maximum 15.8 °C
00:03
20.2 °C
11:43
Mean 15.6 °C
17.3 °C
Last 6hrs  LondonDew Point31-day chart of mean LondonDew Point 31-day chart of min LondonDew Point 31-day chart of max LondonDew Point
Averages, Extremes and Records
Current Station Lifetime (09-25)
Measure 7-day Month 31-day Year 365-day Overall July 2nd Jul
Lowest
Min
6.5 °C
26th
14.8 °C
1st
5.2 °C
6th
-5.5 °C
18th Mar
-5.5 °C
18th Mar
-11.5 °C
2nd Feb 2012
-0.3 °C
Day 19, 2015
4.8 °C
2016
Highest
Max
20.2 °C
1st
20.2 °C
1st
20.2 °C
1st
20.2 °C
1st Jul
24.2 °C
12th Aug
24.2 °C
12th Aug 2024
21.5 °C
Day 19, 2021
18.8 °C
2009
Highest
Min
15.2 °C
Today
15.2 °C
Today
15.2 °C
Today
15.2 °C
29th Jun
17.1 °C
2nd Sep
17.6 °C
12th Aug 2020
16.0 °C
Day 31, 2022
15.2 °C
Today
Lowest
Max
15.8 °C
Today
15.8 °C
Today
9.0 °C
8th
-1.1 °C
14th Feb
-1.1 °C
14th Feb
-7.9 °C
2nd Feb 2012
7.8 °C
Day 9, 2015
9.9 °C
2016
Lowest
Mean
12.9 °C
26th
15.6 °C
Today
7.2 °C
8th
-2.9 °C
10th Jan
-2.9 °C
10th Jan
-9.7 °C
2nd Feb 2012
5.2 °C
Day 9, 2015
7.2 °C
2016
Highest
Mean
17.4 °C
28th
17.3 °C
1st
17.4 °C
28th
17.4 °C
28th Jun
19.7 °C
12th Aug
19.7 °C
12th Aug 2024
18.3 °C
Day 19, 2021
15.6 °C
Today
Averages                
Mean 15.7 °C 16.4 °C 12.7 °C 5.9 °C 8.2 °C 7.4 °C 12.6 °C 11.3 °C
Mean
Minimum
12.8 °C 15.0 °C 10.1 °C 3.4 °C 5.8 °C 4.8 °C 10.1 °C 8.9 °C
Mean
Maximum
18.3 °C 18.0 °C 15.1 °C 8.3 °C 10.6 °C 9.9 °C 15.1 °C 13.8 °C

Past Year Monthly Averages and Extremes (July 2024 - June 2025)
Extremes Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun
Lowest
Min
7.3 °C
4th
9.1 °C
19th
3.5 °C
29th
1.2 °C
11th
-2.3 °C
20th
-0.1 °C
23rd
-5.4 °C
11th
-3.5 °C
17th
-5.5 °C
18th
-2.9 °C
6th
0.1 °C
5th
5.2 °C
2nd
Highest
Max
20.0 °C
19th
24.2 °C
12th
21.1 °C
1st
18.1 °C
16th
13.6 °C
23rd
12.7 °C
5th
11.8 °C
5th
11.4 °C
21st
10.9 °C
22nd
12.1 °C
12th
15.8 °C
29th
19.2 °C
29th
Highest
Min
15.6 °C
20th
14.9 °C
14th
17.1 °C
2nd
13.4 °C
16th
9.7 °C
24th
9.7 °C
1st
7.1 °C
15th
10.0 °C
21st
7.4 °C
22nd
6.3 °C
21st
12.3 °C
30th
15.2 °C
29th
Lowest
Max
13.3 °C
2nd
13.2 °C
21st
8.4 °C
28th
6.0 °C
13th
0.0 °C
21st
4.4 °C
3rd
-0.3 °C
10th
-1.1 °C
14th
0.8 °C
18th
4.9 °C
6th
5.2 °C
4th
9.0 °C
8th
Lowest
Mean
9.5 °C
4th
11.3 °C
21st
5.9 °C
28th
4.0 °C
11th
-1.4 °C
21st
2.1 °C
22nd
-2.9 °C
10th
-2.2 °C
17th
-1.6 °C
15th
1.3 °C
7th
2.8 °C
5th
7.2 °C
8th
Highest
Mean
17.2 °C
20th
19.7 °C
12th
17.9 °C
1st
15.6 °C
16th
12.6 °C
24th
11.0 °C
18th
8.1 °C
15th
10.6 °C
21st
9.4 °C
22nd
9.3 °C
15th
13.9 °C
31st
17.4 °C
28th
Averages Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun
Mean 13.8 °C 14.4 °C 12.4 °C 10.6 °C 6.3 °C 5.9 °C 2.6 °C 2.9 °C 3.4 °C 5.3 °C 8.1 °C 12.3 °C
Mean
Minimum
11.1 °C 11.6 °C 10.0 °C 8.1 °C 4.0 °C 3.9 °C 0.2 °C 1.0 °C 0.7 °C 2.6 °C 5.3 °C 9.7 °C
Mean
Maximum
16.1 °C 17.0 °C 14.7 °C 12.7 °C 8.4 °C 8.1 °C 5.0 °C 4.7 °C 5.9 °C 8.1 °C 10.8 °C 14.8 °C

Past Year Seasonal Averages
Season Daily Min Daily Max Mean
Winter 24/25 1.7 °C
5.9 °C
3.8 °C
Spring 2025 2.9 °C
8.3 °C
5.6 °C
Summer 2024 10.8 °C
16.0 °C
13.5 °C
Autumn 2024 7.4 °C
11.9 °C
9.7 °C

View daily tables of min / max / mean Dew Point data for the past year
View monthly tables of min / max / mean Dew Point data for all months in the station history.

Latest charts and graphs of Dew Point

Past 24hrs and past 12 months trends for Dew Point

Last 24hrs London Dew Point 12 month mean London Dew Point 12month min London Dew Point 12month max London Dew Point

Current year vs last year daily trends for Dew Point

Daily London mean Dew Point vs climate normals

This year min/max daily trends in detail for Dew Point

Current year daily London min Dew Point vs climate normals Current year daily London max Dew Point vs climate normals

View more Dew Point charts

Record Period Averages
Measure 7-day Month July 31-day Year 365-day
Least
Humid
-5.2 °C
Ending 31st Mar 2013
-0.8 °C
Jan 2009
10.0 °C
2011
-2.3 °C
Ending 9th Apr 2013
5.8 °C
2010
5.5 °C
Ending 18th Jul 2013
Most
Humid
18.0 °C
Ending 16th Aug 2020
16.4 °C
Current
16.4 °C
Current
15.4 °C
Ending 15th Aug 2024
9.1 °C
2024
9.4 °C
Ending 4th Jun 2024
Lowest
Mean
Daily-Min
-7.3 °C
Ending 2nd Apr 2013
-3.3 °C
Dec 2010
7.0 °C
2015
-4.9 °C
Ending 9th Apr 2013
3.2 °C
2010
2.9 °C
Ending 18th Jul 2013
Highest
Mean
Daily-Min
16.4 °C
Ending 16th Aug 2020
15.0 °C
Current
15.0 °C
Current
13.0 °C
Ending 11th Sep 2023
6.7 °C
2024
7.1 °C
Ending 4th Jun 2024
Lowest
Mean
Daily-Max
-3.0 °C
Ending 31st Mar 2013
1.6 °C
Dec 2010
12.4 °C
2011
0.3 °C
Ending 9th Apr 2013
8.3 °C
2010
8.2 °C
Ending 27th Dec 2010
Highest
Mean
Daily-Max
20.6 °C
Ending 11th Sep 2023
18.0 °C
Current
18.0 °C
Current
18.0 °C
Ending 16th Aug 2024
11.3 °C
2024
11.7 °C
Ending 4th Jun 2024

Ranked Historical Dew Point Data

Most Humid Days
Rank Min Max Mean
1 17.6 °C
12th Aug 2020
24.2 °C
12th Aug 2024
19.7 °C
12th Aug 2024
2 17.5 °C
11th Aug 2020
22.2 °C
10th Sep 2023
19.1 °C
12th Aug 2020
3 17.1 °C
2nd Sep 2024
21.7 °C
8th Sep 2023
19.0 °C
6th Sep 2016
4 16.9 °C
13th Aug 2020
21.6 °C
6th Sep 2023
18.8 °C
11th Aug 2020
5 16.8 °C
21st Aug 2010
21.5 °C
19th Jul 2021
18.7 °C
10th Sep 2023
6 16.8 °C
6th Sep 2016
21.4 °C
1st Aug 2024
18.6 °C
8th Sep 2023
7 16.8 °C
23rd Aug 2022
21.2 °C
12th Aug 2020
18.5 °C
13th Aug 2020
8 16.6 °C
24th Aug 2022
21.2 °C
12th Jun 2023
18.4 °C
10th Aug 2020
9 16.5 °C
10th Sep 2023
21.1 °C
25th Jul 2019
18.3 °C
19th Jul 2021
10 16.3 °C
7th Sep 2023
21.1 °C
9th Sep 2023
18.2 °C
7th Sep 2023
Least Humid Days
Rank Min Max Mean
1 -11.5 °C
2nd Feb 2012
-7.9 °C
2nd Feb 2012
-9.7 °C
2nd Feb 2012
2 -11.0 °C
5th Apr 2021
-6.2 °C
3rd Feb 2012
-7.8 °C
3rd Feb 2012
3 -10.4 °C
7th Feb 2012
-5.1 °C
13th Feb 2021
-7.2 °C
13th Feb 2021
4 -10.3 °C
12th Mar 2013
-5.0 °C
22nd Feb 2013
-7.2 °C
11th Feb 2012
5 -10.2 °C
11th Feb 2012
-5.0 °C
28th Feb 2018
-6.9 °C
22nd Feb 2013
6 -9.5 °C
1st Feb 2009
-4.5 °C
21st Feb 2013
-6.9 °C
21st Feb 2013
7 -9.4 °C
25th Mar 2017
-4.5 °C
26th Mar 2013
-6.8 °C
28th Feb 2018
8 -9.3 °C
20th Dec 2010
-4.4 °C
25th Mar 2013
-6.7 °C
12th Mar 2013
9 -9.3 °C
2nd Apr 2013
-4.3 °C
12th Feb 2021
-6.3 °C
7th Mar 2010
10 -9.3 °C
28th Feb 2018
-4.1 °C
2nd Feb 2015
-6.0 °C
1st Feb 2012


Most Humid Months
Rank Min Max Mean
1 15.0 °C
Current
18.0 °C
Current
16.4 °C
Current
2 12.4 °C
Jul 2021
17.1 °C
Sep 2023
14.8 °C
Sep 2023
3 12.3 °C
Aug 2020
17.0 °C
Aug 2024
14.7 °C
Jul 2021
4 12.3 °C
Sep 2023
16.8 °C
Jul 2021
14.4 °C
Aug 2020
5 12.1 °C
Aug 2022
16.7 °C
Aug 2022
14.4 °C
Aug 2024
6 11.9 °C
Aug 2023
16.6 °C
Aug 2020
14.4 °C
Aug 2022
7 11.6 °C
Aug 2024
16.2 °C
Aug 2023
14.0 °C
Aug 2023
8 11.4 °C
Aug 2021
16.1 °C
Jul 2024
13.8 °C
Jul 2024
9 11.3 °C
Aug 2019
16.1 °C
Jul 2018
13.5 °C
Jul 2019
10 11.2 °C
Jul 2022
16.0 °C
Jun 2023
13.5 °C
Jul 2022
Least Humid Months
Rank Min Max Mean
1 -3.3 °C
Dec 2010
1.6 °C
Dec 2010
-0.8 °C
Jan 2009
2 -3.0 °C
Mar 2013
1.8 °C
Mar 2013
-0.6 °C
Mar 2013
3 -2.9 °C
Feb 2013
2.2 °C
Jan 2010
-0.5 °C
Dec 2010
4 -2.4 °C
Feb 2018
2.5 °C
Feb 2013
-0.4 °C
Feb 2013
5 -2.4 °C
Jan 2017
2.5 °C
Feb 2018
0.0 °C
Feb 2018
6 -2.2 °C
Feb 2012
3.0 °C
Feb 2012
0.2 °C
Jan 2010
7 -1.7 °C
Jan 2010
3.3 °C
Jan 2017
0.4 °C
Jan 2017
8 -1.6 °C
Apr 2021
4.0 °C
Feb 2015
0.5 °C
Feb 2012
9 -1.6 °C
Feb 2015
4.0 °C
Feb 2009
1.4 °C
Apr 2021
10 -1.5 °C
Feb 2016
4.1 °C
Jan 2019
1.5 °C
Feb 2015


Most Humid Days in July
Rank Min Max Mean
1 16.0 °C
Day 31, 2022
21.5 °C
Day 19, 2021
18.3 °C
Day 19, 2021
2 15.6 °C
Day 26, 2019
21.1 °C
Day 25, 2019
17.9 °C
Day 21, 2021
3 15.6 °C
Day 20, 2024
20.9 °C
Day 27, 2018
17.8 °C
Day 20, 2021
4 15.5 °C
Day 21, 2021
20.9 °C
Day 21, 2021
17.6 °C
Day 26, 2019
5 15.4 °C
Day 20, 2022
20.8 °C
Day 23, 2013
17.5 °C
Day 8, 2023
Least Humid Days in July
Rank Min Max Mean
1 -0.3 °C
Day 19, 2015
7.8 °C
Day 9, 2015
5.2 °C
Day 9, 2015
2 1.0 °C
Day 20, 2015
8.4 °C
Day 1, 2011
5.8 °C
Day 1, 2011
3 2.3 °C
Day 28, 2012
8.9 °C
Day 30, 2015
6.2 °C
Day 30, 2012
4 2.5 °C
Day 30, 2012
9.3 °C
Day 6, 2010
6.8 °C
Day 31, 2015
5 2.5 °C
Day 10, 2015
9.3 °C
Day 11, 2013
6.8 °C
Day 24, 2011

Notes:

  • Valid humidity records began in February 2009
  • All figures, unless specified, relate to the period midnight-midnight, this being when daily extremes are reset
  • 98% is the physical limit of the hygrometer (measuring RH); in reality this tends to means 100% saturation of the air. This value is achieved fairly frequently, any record with this value is just the first instance it occurred in the relevant timeframe.

The different measures of humidity:
The Dew Point (or frost point if the temperature is < 0.0 °C  is the saturation temperature of a parcel of air, i.e. the point at which water condenses out. It is the temperature at which an object would need to be for dew to form on it (dew forms because certain objects - like cars - cool more rapidly than the air, enabling them to reach the dew point). It is directly proportional to the specific humidity, and very well correlated to the absolute humidity. In everyday terms, high dew points are more uncomfortable as sweating is less effective.
Relative Humidity, on the other hand, is rather more abstract and has a very technical definition: the ratio of the partial pressure of water vapour in the air to the saturated vapour pressure of that water. The saturated vapour pressure is proportional to the air temperature, and the partial pressure indicates how much water vapour the air contains, so at a given temperature, the RH is entirely dependent on this partial pressure, making the RH useful in determining the extent to which the air is water-saturated. For example: When it rains the relative humidity will increase, but the dew point may not, as the temperature will usually fall as well. If the dew point is the same when the RH increases, the air has the same amount of water but it is cooler, so it is more saturated, as less water vapour can exist in cooler air.
Simply and concisely: Dew point is a rough measure of how much water vapour is physically in the air; relative humidity is just a measure of the degree to which the air is full of water vapour (i.e. its saturation). One is an absolute measure, the other is relative.