Historical Ranked Periods - Day Maximum (09-21) / °C · 5-day mean
Top 5-day mean
#
Value
Date
1
33.7
23–27 Jun 2026
2
33.2
7–11 Aug 2020
3
33.0
6–10 Jul 2026
4
32.2
16–20 Jul 2022
5
31.8
22–26 May 2026
6
31.6
11–15 Aug 2022
7
31.4
17–21 Jun 2017
8
31.3
23–27 Jul 2018
9
31.1
27 Jun – 1 Jul 2025
10
30.7
22–26 Jul 2019
11
30.6
6–10 Sep 2023
12
30.3
23–27 Aug 2019
13
30.3
18–22 Jul 2021
14
30.2
3–7 Aug 2018
15
30.0
5–9 Jul 2018
16
30.0
13–17 Jul 2013
17
30.0
17–21 Jun 2025
18
29.5
9–13 Jul 2025
19
29.4
25–29 Jul 2026
20
29.3
8–12 Jul 2022
21
29.3
16–20 Jul 2016
22
29.3
11–15 Aug 2025
23
29.1
5–9 Jul 2017
24
29.1
10–14 Jun 2023
25
28.9
22–26 Jun 2020
Bottom 5-day mean
#
Value
Date
1
-0.3
26 Feb – 2 Mar 2018
2
-0.1
29 Nov – 3 Dec 2010
3
0.2
16–20 Jan 2013
4
0.3
17–21 Dec 2010
5
0.3
7–11 Feb 2021
6
0.4
5–9 Jan 2010
7
0.5
11–15 Dec 2022
8
1.0
22–26 Dec 2010
9
1.1
18–22 Dec 2009
10
1.4
6–10 Jan 2009
11
1.4
7–11 Feb 2012
12
1.5
10–14 Jan 2010
13
1.5
23–27 Mar 2013
14
1.5
31 Jan – 4 Feb 2012
15
1.9
5–9 Dec 2010
16
2.0
21–25 Jan 2013
17
2.1
24–28 Nov 2010
18
2.1
21–25 Feb 2013
19
2.4
2–6 Feb 2009
20
2.5
1–5 Jan 2009
21
2.5
8–12 Jan 2025
22
2.5
2–6 Jan 2026
23
2.6
27–31 Jan 2011
24
2.8
31 Dec 2009 – 4 Jan 2010
25
2.8
9–13 Feb 2013
Day Maximum (09-21) 5-day extremes: highest and lowest period means.
There are 6419 valid 5-day periods from 2009 to present in London, NW3 (complete windows only, hiding overlapping windows). Data for Day Maximum (09-21) begins in 1881.
Highest air temperature during the daytime window 09:00 to 21:00 local time.