Daily Report for 25th April 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 7.3 °C (+0.8) 23:58 7.0 °C (+1.1) 11.3 °C (+4.8), 2015 1.4 °C (-5.1), 2017
Maximum Temperature 16.1 °C (+0.8) 14:39 16.3 °C (+2.1) 22.4 °C (+7.1), 2013 10.7 °C (-4.6), 2023
Mean Temperature 11.4 °C (+0.8) 11.1 °C (+1.6) 16.4 °C, 2013 6.0 °C, 2017
Minimum Humidity 38% 17:01 55% 82%, 2014 33%, 2011
Maximum Humidity 81% 09:48 91% 97%, 2014 67%, 2017
Mean Humidity 59% 75% 93%, 2014 48%, 2017
Minimum Pressure 1003 hPa 06:18 1012 hPa 1027 hPa, 2021 982 hPa, 2012
Maximum Pressure 1011 hPa 23:32 1018 hPa 1031 hPa, 2021 998 hPa, 2012
Mean Pressure 1007 hPa 1015 hPa 1029 hPa, 2021 990 hPa, 2012
Mean Wind Speed 3.9 mph (-1.0) 4.1 mph (-0.8) 8.4 mph, 2018 3.8 mph, 2014
Maximum Wind Speed n/a 0.0 mph 25.6, 2012 10.2, 2014
Maximum Gust 20.0 mph 19.1 mph 45.3 mph, 2012 15.0 mph, 2023
Mean Wind Direction n/a
Rainfall 0.5 mm 27.9 mm (80%) 14.2 mm, 2012
Maximum Hourly Rain 0.5 mm 08:32 4.3 mm, 2012
Maximum 10-min Rain 0.5 mm 08:32 2.2 mm, 2022
Maximum Rain Rate 4.1 mm/h 08:32 40 mm/h, 2012
Minimum Dew Point 0.2 °C 23:09 3.5 °C 6.9 °C, 2014 -6.7 °C, 2017
Maximum Dew Point 7.7 °C 10:04 9.2 °C 12.5 °C, 2014 -1.2 °C, 2017
Mean Dew Point 3.4 °C 6.3 °C 9.5 °C, 2013 -4.4 °C, 2017
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 8.5 °C * 7.2 °C 11.3 °C, 2015 1.4 °C, 2017
Day Maximum (09-21) 16.1 °C 16.2 °C 22.4 °C, 2013 10.7 °C, 2023
Max 10m Temp Rise 0.8 °C 13:19 0.5 °C 0.9 °C, 2019 0.2 °C, 2014
Max 1hr Temp Rise 2.7 °C 13:26 1.6 °C 2.7 °C, 2009 0.8 °C, 2014
Max 1hr Hum Rise 9% 09:02 4% 19%, 2022 4%, 2014
Max 10m Temp Fall 0.5 °C 14:17 0.4 °C 1.6 °C, 2022 0.4 °C, 2015
Max 1hr Temp Fall 1.5 °C 18:50 1.1 °C 3.8 °C, 2013 1.5 °C, 2009
Max 1hr Hum Fall 16% 13:47 6% 19%, 2019 2%, 2014
Max 10m Wind Speed n/a 0.0 mph 13.9, 2018 7.5, 2020
Minimum Feels-like n/a 0.0 °C 12.5, 2015 -2.9, 2017
Maximum Feels-like n/a 0.0 °C 23.5, 2013 10.7, 2023
Mean Feels-like n/a 0.0 °C 17.5, 2013 3.6, 2017
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 8.8 °C (+0.0) 9.3 °C (+1.0) 11.6 °C (+2.8), 2013 4.5 °C (-4.3), 2014
Humidity Range 43% 36% 55%, 2013 15%, 2014
Pressure Range 8 hPa 6 hPa 16 hPa, 2012 3 hPa, 2011
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 6.3 [48%]153 hrs (115%) [49%] 13 [100%], 2011 0 [0%], 2014
Wet Hours 1
[Mean rain rate: 0.5 mm/h]
34 hrs (89%) [5.7%] 9, 2012 0, 2011
Cloud Cover not available
Events None
Comments ~08-09 Moderate Rain
Extra Comments
Issues None known
Observer Absent? No
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 25th April 2009.
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

daygraph daygraph 2 daygraph-wdir

Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose