Daily Report for 4th September 2026

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 15.1 °C (+2.5) 23:55 15.6 °C (+2.9) 15.9 °C (+3.3), 2016 10.1 °C (-2.5), 2010
Maximum Temperature 20.7 °C (-0.3) 08:04 22.4 °C (+1.4) 28.3 °C (+7.3), 2023 15.3 °C (-5.7), 2015
Mean Temperature 19.3 °C (+1.1) 19.3 °C (+2.2) 21.1 °C, 2023 12.8 °C, 2015
Minimum Humidity 56% 17:02 56% 80%, 2017 38%, 2023
Maximum Humidity 88% 09:34 86% 97%, 2017 84%, 2015
Mean Humidity 73% 72% 90%, 2017 67%, 2009
Minimum Pressure 1011 hPa 07:31 1016 hPa 1022 hPa, 2012 1003 hPa, 2009
Maximum Pressure 1020 hPa 23:56 1021 hPa 1028 hPa, 2023 1007 hPa, 2011
Mean Pressure 1015 hPa 1018 hPa 1024 hPa, 2023 1006 hPa, 2011
Mean Wind Speed 8.5 mph (+4.6) 6.7 mph (+2.8) 9.0 mph, 2016 1.4 mph, 2024
Maximum Wind Speed 19.7 mph 07:58 16.4 mph 20.2 mph, 2016 7.8 mph, 2014
Maximum Gust 32.3 mph 07:59 25.9 mph 32.3 mph, 2016 10.7 mph, 2014
Mean Wind Direction WNW
Rainfall 1.8 mm 2.0 mm (30%) 8.8 mm, 2017
Maximum Hourly Rain 1.8 mm 09:06 3.3 mm, 2011
Maximum 10-min Rain 1.6 mm 08:58 1.6 mm, 2026
Maximum Rain Rate 14 mm/h 08:54 24 mm/h, 2025
Minimum Dew Point 10.4 °C 17:32 11.8 °C 13.2 °C, 2016 4.9 °C, 2009
Maximum Dew Point 17.8 °C 08:48 16.3 °C 18.6 °C, 2017 9.3 °C, 2009
Mean Dew Point 14.3 °C 13.9 °C 15.7 °C, 2017 7.4 °C, 2009
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 19.1 °C * 08:59 16.6 °C 19.1 °C, 2026 10.1 °C, 2010
Day Maximum (09-21) * 20.3 °C * 11:53 22.3 °C 28.3 °C, 2023 15.3 °C, 2015
Max 10m Temp Rise 0.5 °C 11:15 0.6 °C 0.9 °C, 2010 0.4 °C, 2016
Max 1hr Temp Rise 1.4 °C 11:20 1.9 °C 4.0 °C, 2023 1.0 °C, 2016
Max 1hr Hum Rise 6% 20:46 8% 13%, 2020 3%, 2017
Max 10m Temp Fall 1.4 °C 09:03 0.7 °C 1.4 °C, 2026 0.2 °C, 2014
Max 1hr Temp Fall 2.7 °C 09:16 1.6 °C 2.7 °C, 2026 0.7 °C, 2014
Max 1hr Hum Fall 10% 11:30 11% 20%, 2023 5%, 2021
Max 10m Wind Speed 14.6 mph 08:02 12.2 mph 16.5 mph, 2016 5.1 mph, 2024
Minimum Feels-like 16.7 °C 23:52 18.0 °C 20.1 °C, 2016 10.3 °C, 2015
Maximum Feels-like 26.3 °C 08:18 26.8 °C 33.0 °C, 2023 16.4 °C, 2015
Mean Feels-like 22.9 °C 22.8 °C 25.2 °C, 2023 13.2 °C, 2015
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Minimum PM2.5 0 05:12 1 0, 2026 0, 2021
Maximum PM2.5 12 22:55 9 12, 2026 12, 2026
Mean PM2.5 3 3 3, 2026 3, 2026
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 5.6 °C (-2.8) 6.9 °C (-1.5) 13.3 °C (+4.9), 2013 3.7 °C (-4.7), 2016
Humidity Range 32% 30% 58%, 2023 12%, 2021
Pressure Range 9 hPa 5 hPa 13 hPa, 2009 2 hPa, 2018
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0.2 [2%]12 hrs (55%) [24%] 12 [99%], 2013 0.1 [1%], 2016
Wet Hours 1
[Mean rain rate: 1.8 mm/h]		2 hrs (37%) [2.1%] 11, 2017 0, 2009
Cloud Cover unknown
Events None
Comments data is awaiting quality control from site operator
Extra Comments
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature @ Hampstead Heath 19.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 4th September 2026.
Times of extremes are computed using the midpoint of the longest continuous period at that extreme value.
Cumulative anomalies are reported according to the expected value for the month-to-date rather than month-end.
Sun hrs are derived based on analysis of webcam observations, but may use data from our closest site, Heathrow, when needed.
Wet hrs are dervied algorithmically from rainfall data, though may be adjusted manually.
Rainfall totals may be manually adjusted after the fact to correct delayed or erroneous data.
Cloud cover and Events are manually reported, often with multi-week delays.
Data is generally reliable and accurate but should always be viewed with some quantity of salt to hand.
View monthly summary

Daily Graph of Conditions

day graph

Webcam Summary of Cloud Conditions

daycamsumFull resolution individual images at up-to 5 minute intervals

Wind rose