Humidity Type:
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Detailed Dew Point Data

Current
Measure Value
Dew Point -0.3 °C
Dew Pt Trend -0.7 °C /hr
24hr Mean Dew Pt 2.0 °C
Wet-Bulb Temperature 0.3 °C
Absolute Humidity 4.80 gm-3
Air Density 1281.21 gm-3
Recent Averages and Extremes
Measure Today Yesterday
Minimum -0.6 °C
08:01		 1.2 °C
23:57
Maximum 2.2 °C
04:01		 4.3 °C
00:09
Mean 1.4 °C
 2.7 °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 (09-23)
Measure 7-day Month 31-day Year 365-day Overall Nov 29th Nov
Lowest
Min		 -1.9 °C
25th		 -1.9 °C
25th		 -1.9 °C
25th		 -6.3 °C
17th Jan		 -6.6 °C
15th Dec		 -11.5 °C
2nd Feb 2012		 -7.4 °C
Day 21, 2015		 -5.7 °C
2016
Highest
Max		 10.0 °C
23rd		 13.9 °C
18th		 13.9 °C
18th		 22.2 °C
10th Sep		 22.2 °C
10th Sep		 22.2 °C
10th Sep 2023		 15.8 °C
Day 1, 2009		 11.4 °C
2018
Highest
Min		 7.1 °C
23rd		 8.6 °C
13th		 8.6 °C
19th		 16.5 °C
10th Sep		 16.5 °C
10th Sep		 17.6 °C
12th Aug 2020		 12.5 °C
Day 6, 2015		 6.8 °C
2018
Lowest
Max		 0.8 °C
25th		 0.8 °C
25th		 0.8 °C
25th		 -1.6 °C
17th Jan		 -1.7 °C
15th Dec		 -7.9 °C
2nd Feb 2012		 -2.2 °C
Day 28, 2010		 -1.0 °C
2016
Lowest
Mean		 -0.6 °C
25th		 -0.6 °C
25th		 -0.6 °C
25th		 -3.6 °C
17th Jan		 -4.2 °C
15th Dec		 -9.7 °C
2nd Feb 2012		 -4.8 °C
Day 28, 2010		 -4.1 °C
2016
Highest
Mean		 9.0 °C
23rd		 11.1 °C
18th		 11.1 °C
18th		 18.7 °C
10th Sep		 18.7 °C
10th Sep		 19.1 °C
12th Aug 2020		 13.8 °C
Day 6, 2015		 9.5 °C
2018
Averages                
Mean 3.4 °C 6.5 °C 6.6 °C 9.2 °C 8.7 °C 7.3 °C 6.2 °C 3.6 °C
Mean
Minimum		 0.9 °C 4.2 °C 4.2 °C 6.7 °C 6.3 °C 4.7 °C 3.7 °C 1.3 °C
Mean
Maximum		 6.0 °C 8.7 °C 8.9 °C 11.5 °C 11.0 °C 9.9 °C 8.6 °C 5.7 °C

Past Year Monthly Averages and Extremes (November 2022 - October 2023)
Extremes Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct
Lowest
Min		 1.9 °C
21st		 -6.6 °C
15th		 -6.3 °C
17th		 -3.6 °C
8th		 -4.0 °C
11th		 -1.8 °C
4th		 3.5 °C
28th		 3.0 °C
14th		 7.8 °C
26th		 8.7 °C
31st		 7.1 °C
23rd		 0.0 °C
16th
Highest
Max		 13.2 °C
6th		 12.0 °C
31st		 11.7 °C
4th		 11.2 °C
17th		 11.7 °C
30th		 12.8 °C
28th		 14.0 °C
7th		 21.2 °C
12th		 19.8 °C
8th		 19.3 °C
11th		 22.2 °C
10th		 18.6 °C
1st
Highest
Min		 9.3 °C
8th		 9.1 °C
31st		 8.1 °C
4th		 8.9 °C
17th		 9.1 °C
17th		 7.0 °C
28th		 10.4 °C
7th		 15.9 °C
28th		 14.8 °C
27th		 15.3 °C
18th		 16.5 °C
10th		 15.0 °C
2nd
Lowest
Max		 6.4 °C
22nd		 -1.7 °C
15th		 -1.6 °C
17th		 1.2 °C
26th		 1.0 °C
5th		 3.2 °C
25th		 7.4 °C
3rd		 10.1 °C
2nd		 11.6 °C
2nd		 13.3 °C
6th		 11.2 °C
23rd		 4.9 °C
15th
Lowest
Mean		 4.7 °C
22nd		 -4.2 °C
15th		 -3.6 °C
17th		 -0.7 °C
26th		 -0.3 °C
5th		 1.3 °C
25th		 5.7 °C
3rd		 7.9 °C
2nd		 9.9 °C
2nd		 10.9 °C
30th		 8.9 °C
23rd		 3.0 °C
15th
Highest
Mean		 11.4 °C
7th		 11.1 °C
19th		 10.0 °C
4th		 10.2 °C
17th		 10.0 °C
17th		 10.8 °C
28th		 12.2 °C
7th		 17.1 °C
28th		 17.5 °C
8th		 17.2 °C
18th		 18.7 °C
10th		 16.2 °C
2nd
Averages Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct
Mean 8.4 °C 3.3 °C 3.6 °C 4.2 °C 5.1 °C 5.6 °C 9.2 °C 13.0 °C 13.3 °C 14.0 °C 14.8 °C 11.1 °C
Mean
Minimum		 6.2 °C 1.3 °C 0.8 °C 1.7 °C 2.9 °C 2.9 °C 6.9 °C 10.0 °C 11.1 °C 11.9 °C 12.3 °C 8.7 °C
Mean
Maximum		 10.3 °C 5.5 °C 6.0 °C 6.5 °C 7.5 °C 7.9 °C 11.6 °C 16.0 °C 15.3 °C 16.2 °C 17.1 °C 13.3 °C

Past Year Seasonal Averages
Season Daily Min Daily Max Mean
Winter 22/23 1.3 °C
 6.0 °C
 3.7 °C
Spring 2023 4.2 °C
 9.0 °C
 6.7 °C
Summer 2023 11.0 °C
 15.9 °C
 13.4 °C
Autumn 2022 9.1 °C
 13.6 °C
 11.4 °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 Nov 31-day Year 365-day
Least
Humid		 -5.2 °C
Ending 31st Mar 2013		 -0.8 °C
Jan 2009		 2.9 °C
2016		 -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		 14.8 °C
Sep 2023		 8.5 °C
2011		 15.2 °C
Ending 12th Sep 2023		 9.2 °C
2023		 9.0 °C
Ending 13th Oct 2023
Lowest
Mean
Daily-Min		 -7.3 °C
Ending 2nd Apr 2013		 -3.3 °C
Dec 2010		 0.4 °C
2016		 -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		 12.4 °C
Jul 2021		 6.2 °C
2022		 13.0 °C
Ending 11th Sep 2023		 6.7 °C
2023		 6.6 °C
Ending 12th Oct 2023
Lowest
Mean
Daily-Max		 -3.0 °C
Ending 31st Mar 2013		 1.6 °C
Dec 2010		 5.2 °C
2016		 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		 17.1 °C
Sep 2023		 11.0 °C
2011		 17.5 °C
Ending 12th Sep 2023		 11.5 °C
2023		 11.3 °C
Ending 13th Oct 2023

Ranked Historical Dew Point Data

Most Humid Days
Rank Min Max Mean
1 17.6 °C
12th Aug 2020		 22.2 °C
10th Sep 2023		 19.1 °C
12th Aug 2020
2 17.5 °C
11th Aug 2020		 21.7 °C
8th Sep 2023		 19.0 °C
6th Sep 2016
3 16.9 °C
13th Aug 2020		 21.6 °C
6th Sep 2023		 18.8 °C
11th Aug 2020
4 16.8 °C
21st Aug 2010		 21.5 °C
19th Jul 2021		 18.7 °C
10th Sep 2023
5 16.8 °C
6th Sep 2016		 21.2 °C
12th Aug 2020		 18.6 °C
8th Sep 2023
6 16.8 °C
23rd Aug 2022		 21.2 °C
12th Jun 2023		 18.5 °C
13th Aug 2020
7 16.6 °C
24th Aug 2022		 21.1 °C
25th Jul 2019		 18.4 °C
10th Aug 2020
8 16.5 °C
10th Sep 2023		 21.1 °C
9th Sep 2023		 18.3 °C
19th Jul 2021
9 16.3 °C
7th Sep 2023		 20.9 °C
27th Jul 2018		 18.2 °C
7th Sep 2023
10 16.2 °C
10th Aug 2020		 20.9 °C
21st Jul 2021		 18.2 °C
23rd Aug 2022
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 12.4 °C
Jul 2021		 17.1 °C
Sep 2023		 14.8 °C
Sep 2023
2 12.3 °C
Aug 2020		 16.8 °C
Jul 2021		 14.7 °C
Jul 2021
3 12.3 °C
Sep 2023		 16.7 °C
Aug 2022		 14.4 °C
Aug 2020
4 12.1 °C
Aug 2022		 16.6 °C
Aug 2020		 14.4 °C
Aug 2022
5 11.9 °C
Aug 2023		 16.2 °C
Aug 2023		 14.0 °C
Aug 2023
6 11.4 °C
Aug 2021		 16.1 °C
Jul 2018		 13.5 °C
Jul 2019
7 11.3 °C
Aug 2019		 16.0 °C
Jun 2023		 13.5 °C
Jul 2022
8 11.2 °C
Jul 2022		 15.8 °C
Sep 2021		 13.5 °C
Jul 2018
9 11.1 °C
Jul 2023		 15.7 °C
Aug 2019		 13.5 °C
Sep 2021
10 11.0 °C
Jul 2019		 15.7 °C
Jul 2019		 13.5 °C
Aug 2019
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 November
Rank Min Max Mean
1 12.5 °C
Day 6, 2015		 15.8 °C
Day 1, 2009		 13.8 °C
Day 6, 2015
2 12.4 °C
Day 5, 2015		 15.5 °C
Day 6, 2015		 13.2 °C
Day 7, 2015
3 12.1 °C
Day 10, 2015		 15.2 °C
Day 1, 2020		 13.2 °C
Day 5, 2015
4 11.6 °C
Day 4, 2010		 15.0 °C
Day 7, 2015		 13.1 °C
Day 3, 2011
5 11.5 °C
Day 3, 2011		 15.0 °C
Day 2, 2020		 12.9 °C
Day 10, 2015
Least Humid Days in November
Rank Min Max Mean
1 -7.4 °C
Day 21, 2015		 -2.2 °C
Day 28, 2010		 -4.8 °C
Day 28, 2010
2 -7.2 °C
Day 22, 2015		 -1.5 °C
Day 26, 2010		 -4.1 °C
Day 29, 2016
3 -6.7 °C
Day 28, 2010		 -1.0 °C
Day 29, 2016		 -3.8 °C
Day 30, 2016
4 -6.4 °C
Day 30, 2016		 -0.9 °C
Day 29, 2010		 -3.6 °C
Day 26, 2010
5 -5.8 °C
Day 27, 2010		 -0.9 °C
Day 28, 2021		 -3.2 °C
Day 27, 2010

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.