Daily Report for 31st March 2021

<<Previous Day
Reset
Next Day>>
Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 7.3 °C (+2.8) 05:47 4.2 °C (+0.6) 11.2 °C (+6.7), 2017 -2.6 °C (-7.1), 2013
Maximum Temperature 21.1 °C (+9.5) 13:10 11.1 °C (+0.8) 21.1 °C (+9.5), 2021 5.6 °C (-6.0), 2013
Mean Temperature 14.4 °C (+6.2) 7.7 °C (+0.7) 14.4 °C, 2021 1.8 °C, 2013
Minimum Humidity 50% 16:51 64% 75%, 2018 37%, 2015
Maximum Humidity 84% 07:24 89% 97%, 2011 73%, 2009
Mean Humidity 67% 78% 87%, 2018 56%, 2015
Minimum Pressure 1019 hPa 18:25 1019 hPa 1030 hPa, 2020 981 hPa, 2010
Maximum Pressure 1025 hPa 00:01 1026 hPa 1034 hPa, 2020 1001 hPa, 2010
Mean Pressure 1022 hPa 1023 hPa 1032 hPa, 2020 991 hPa, 2010
Mean Wind Speed 1.0 mph (-4.2) 5.5 mph (+0.3) 12.7 mph, 2015 1.0 mph, 2021
Maximum Wind Speed 7.3 mph 12:27 14.1 mph 30.1 mph, 2015 7.3 mph, 2021
Maximum Gust 10.3 mph 12:27 21.1 mph 39.8 mph, 2015 10.3 mph, 2021
Mean Wind Direction SW
Rainfall 0.0 mm 21.5 mm (51%) 3.0 mm, 2011
Maximum Hourly Rain n/a 2, 2018
Maximum 10-min Rain n/a 0.7, 2018
Maximum Rain Rate n/a 3.3, 2018
Minimum Dew Point 4.4 °C 05:34 1.4 °C 8.0 °C, 2011 -7.5 °C, 2013
Maximum Dew Point 11.4 °C 12:55 6.3 °C 12.6 °C, 2011 -1.6 °C, 2013
Mean Dew Point 8.1 °C 3.9 °C 9.6 °C, 2011 -5.2 °C, 2013
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 7.3 °C 05:47 4.6 °C 13.0 °C, 2017 -2.6 °C, 2013
Day Maximum (09-21) 21.1 °C 13:11 11.1 °C 21.1 °C, 2021 5.6 °C, 2013
Max 10m Temp Rise 0.9 °C 08:56 0.5 °C 0.9 °C, 2013 0.3 °C, 2012
Max 1hr Temp Rise 3.9 °C 09:21 1.7 °C 3.9 °C, 2021 0.8 °C, 2012
Max 1hr Hum Rise 9% 21:18 8% 17%, 2015 5%, 2017
Max 10m Temp Fall 0.5 °C 20:52 0.5 °C 1.0 °C, 2015 0.2 °C, 2017
Max 1hr Temp Fall 2.2 °C 21:42 1.6 °C 2.2 °C, 2015 1.0 °C, 2013
Max 1hr Hum Fall 14% 09:10 9% 25%, 2015 9%, 2014
Max 10m Wind Speed 5.0 mph 12:28 10.8 mph 21.3 mph, 2015 5.0 mph, 2021
Minimum Feels-like 7.3 °C 05:47 1.0 °C 11.2 °C, 2017 -6.1 °C, 2013
Maximum Feels-like 22.9 °C 13:10 11.3 °C 22.9 °C, 2021 4.0 °C, 2013
Mean Feels-like 15.2 °C 6.2 °C 15.2 °C, 2021 -0.8 °C, 2013
Air-frost Hrs 0 hrs 0.1 hrs 7 hrs, 2013 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 13.8 °C (+6.7) 7.0 °C (+0.2) 13.8 °C (+6.7), 2021 3.4 °C (-3.7), 2010
Humidity Range 34% 26% 53%, 2015 18%, 2018
Pressure Range 6 hPa 7 hPa 22 hPa, 2015 2 hPa, 2013
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 1 [9%]95 hrs (89%) [29%] 8 [69%], 2016 0.1 [1%], 2012
Wet Hours 025 hrs (47%) [3.4%] 4, 2011 , 2009
Cloud Cover am: Hazy transitioned to Overcast
pm: Overcast
Events None
Comments -
Extra Comments
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 4.5 °C
Notes
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 initially pulled from the official weather station at Heathrow, and later adjusted by hand to reflect local conditions based on webcam observations. Wet hrs are dervied algorithmically from rainfall data, though may be adjusted manually. Cloud cover and Events are manually reported, often with multi-week delays.
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