Daily Report for 23rd March 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 6.0 °C (+1.2) 23:52 3.6 °C (-0.5) 9.2 °C (+4.4), 2023 0.4 °C (-4.4), 2013
Maximum Temperature 11.9 °C (+0.2) 13:14 12.7 °C (+2.0) 19.5 °C (+7.8), 2012 2.6 °C (-9.1), 2013
Mean Temperature 8.9 °C (+0.7) 8.1 °C (+0.8) 12.5 °C, 2012 0.9 °C, 2013
Minimum Humidity 56% 19:47 53% 89%, 2013 36%, 2022
Maximum Humidity 85% 07:23 92% 98%, 2010 76%, 2020
Mean Humidity 70% 73% 96%, 2013 64%, 2020
Minimum Pressure 1012 hPa 15:55 1012 hPa 1038 hPa, 2011 995 hPa, 2023
Maximum Pressure 1029 hPa 00:13 1021 hPa 1042 hPa, 2011 1000 hPa, 2023
Mean Pressure 1020 hPa 1017 hPa 1040 hPa, 2011 998 hPa, 2023
Mean Wind Speed 7.2 mph (+2.0) 4.9 mph (-0.3) 10.5 mph, 2023 0.8 mph, 2022
Maximum Wind Speed n/a 0.0 mph 23.2, 2023 5.8, 2016
Maximum Gust 28.0 mph 21.5 mph 34.6 mph, 2023 8.7 mph, 2012
Mean Wind Direction n/a
Rainfall 0.8 mm 25.0 mm (86%) 6.8 mm, 2013
Maximum Hourly Rain 0.8 mm 15:19 1.4 mm, 2010
Maximum 10-min Rain 0.5 mm 15:19 0.5 mm, 2009
Maximum Rain Rate n/a 15:19 3, 2017
Minimum Dew Point -1.8 °C 20:55 0.5 °C 6.5 °C, 2023 -3.4 °C, 2014
Maximum Dew Point 5.4 °C 15:15 5.9 °C 10.0 °C, 2023 1.1 °C, 2013
Mean Dew Point 2.7 °C 3.0 °C 8.3 °C, 2023 -0.1 °C, 2014
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 6.0 °C 3.8 °C 9.2 °C, 2023 0.4 °C, 2013
Day Maximum (09-21) 11.9 °C 12.7 °C 19.5 °C, 2012 0.9 °C, 2013
Max 10m Temp Rise 0.8 °C 08:53 0.3 °C 0.8 °C, 2009 0.1 °C, 2013
Max 1hr Temp Rise 1.8 °C 09:43 0.8 °C 3.8 °C, 2011 0.3 °C, 2013
Max 1hr Hum Rise 11% 15:31 3% 15%, 2015 3%, 2013
Max 10m Temp Fall 1.0 °C 15:22 0.3 °C 1.1 °C, 2014 0.2 °C, 2010
Max 1hr Temp Fall 2.8 °C 16:03 0.7 °C 2.8 °C, 2009 0.7 °C, 2013
Max 1hr Hum Fall 17% 17:36 4% 19%, 2018 1%, 2013
Max 10m Wind Speed n/a 0.0 mph 17.8, 2023 3.9, 2016
Minimum Feels-like n/a 0.0 °C 5.4, 2023 -6.1, 2013
Maximum Feels-like n/a 0.0 °C 19.5, 2012 1, 2013
Mean Feels-like n/a 0.0 °C 12.5, 2012 -3.4, 2013
Air-frost Hrs 0 hrs 0.0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 5.9 °C (-1.0) 9.1 °C (+2.6) 13.9 °C (+7.0), 2012 2.2 °C (-4.7), 2013
Humidity Range 29% 40% 56%, 2012 9%, 2013
Pressure Range 17 hPa 8 hPa 17 hPa, 2009 2 hPa, 2012
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 2.3 [21%]136 hrs (165%) [56%] 11.2 [101%], 2020 0 [0%], 2013
Wet Hours 0 hrs (0%) [0%] 18, 2013 , 2009
Cloud Cover not available
Events None
Comments 1530 H. Showerower, SL. Rain to 1630
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 23rd March 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.
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Daily Graph of Conditions

daygraph daygraph 2 daygraph-wdir

Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose