Daily Report for 25th April 2015

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 11.3 °C (+4.8) 05:56 5.9 °C (-0.0) 11.3 °C (+4.8), 2015 1.4 °C (-5.1), 2017
Maximum Temperature 17.8 °C (+2.5) 15:12 15.9 °C (+1.7) 22.4 °C (+7.1), 2013 10.7 °C (-4.6), 2023
Mean Temperature 13.7 °C (+3.6) 10.9 °C (+0.8) 16.4 °C, 2013 6.0 °C, 2017
Minimum Humidity 46% 15:52 44% 82%, 2014 33%, 2011
Maximum Humidity 93% 09:29 85% 97%, 2014 67%, 2017
Mean Humidity 75% 65% 93%, 2014 48%, 2017
Minimum Pressure 1004 hPa 17:39 1020 hPa 1027 hPa, 2021 982 hPa, 2012
Maximum Pressure 1008 hPa 00:45 1027 hPa 1031 hPa, 2021 998 hPa, 2012
Mean Pressure 1006 hPa 1023 hPa 1029 hPa, 2021 990 hPa, 2012
Mean Wind Speed 6.6 mph (+1.7) 5.0 mph (+0.1) 8.4 mph, 2018 3.0 mph, 2024
Maximum Wind Speed 14.7 mph 14:02 12.5 mph 25.6 mph, 2012 10.2 mph, 2014
Maximum Gust 22.8 mph 13:40 17.6 mph 45.3 mph, 2012 15.0 mph, 2023
Mean Wind Direction SW
Rainfall 3.0 mm 13.0 mm (37%) 14.2 mm, 2012
Maximum Hourly Rain 1.3 mm 09:08 4.3 mm, 2012
Maximum 10-min Rain 0.4 mm 08:42 2.2 mm, 2022
Maximum Rain Rate 3.6 mm/h 08:35 40 mm/h, 2012
Minimum Dew Point 5.3 °C 16:02 0.7 °C 6.9 °C, 2014 -6.7 °C, 2017
Maximum Dew Point 12.2 °C 10:36 7.3 °C 12.5 °C, 2014 -1.2 °C, 2017
Mean Dew Point 9.0 °C 3.9 °C 9.5 °C, 2013 -4.4 °C, 2017
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 11.3 °C 05:56 6.1 °C 11.3 °C, 2015 1.4 °C, 2017
Day Maximum (09-21) 17.8 °C 15:12 15.9 °C 22.4 °C, 2013 10.7 °C, 2023
Max 10m Temp Rise 0.6 °C 11:39 0.6 °C 0.9 °C, 2019 0.2 °C, 2014
Max 1hr Temp Rise 1.8 °C 10:36 2.3 °C 2.7 °C, 2009 0.8 °C, 2014
Max 1hr Hum Rise 12% 20:05 9% 19%, 2022 4%, 2014
Max 10m Temp Fall 0.4 °C 19:56 0.5 °C 1.6 °C, 2022 0.4 °C, 2015
Max 1hr Temp Fall 1.5 °C 20:12 2.0 °C 3.8 °C, 2013 1.5 °C, 2009
Max 1hr Hum Fall 16% 14:24 13% 19%, 2019 2%, 2014
Max 10m Wind Speed 10.2 mph 14:24 9.6 mph 13.9 mph, 2018 7.5 mph, 2020
Minimum Feels-like 12.5 °C 05:51 3.6 °C 12.5 °C, 2015 -2.9 °C, 2017
Maximum Feels-like 17.8 °C 15:10 16.0 °C 23.5 °C, 2013 10.7 °C, 2023
Mean Feels-like 14.6 °C 10.3 °C 17.5 °C, 2013 3.6 °C, 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 6.5 °C (-2.3) 10.0 °C (+1.7) 11.6 °C (+2.8), 2013 4.5 °C (-4.3), 2014
Humidity Range 47% 41% 55%, 2013 15%, 2014
Pressure Range 4 hPa 7 hPa 16 hPa, 2012 3 hPa, 2011
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 2 [15%]174 hrs (131%) [56%] 13 [100%], 2011 0 [0%], 2014
Wet Hours 5
[Mean rain rate: 0.6 mm/h]		23 hrs (59%) [3.8%] 9, 2012 0, 2011
Cloud Cover Mostly Cloudy with periods of Partly Cloudy
Events None
Comments o.night, 08,19-22 Rain/Showers
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 2015.
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.
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Daily Graph of Conditions

day graph

Webcam Summary of Cloud Conditions

daycamsumLarge resolution version

Wind rose