Daily Report for 22nd July 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 14.4 °C (-0.3) 06:11 13.8 °C (-0.2) 17.5 °C (+2.8), 2016 10.5 °C (-4.2), 2011
Maximum Temperature 20.8 °C (-2.5) 16:39 22.0 °C (-1.0) 32.7 °C (+9.4), 2013 18.2 °C (-5.1), 2023
Mean Temperature 17.5 °C (-1.4) 17.3 °C (-0.6) 24.5 °C, 2013 15.4 °C, 2017
Minimum Humidity 53% 16:06 53% 70%, 2023 31%, 2013
Maximum Humidity 92% 05:38 90% 95%, 2023 71%, 2020
Mean Humidity 74% 74% 85%, 2023 55%, 2020
Minimum Pressure 1001 hPa 20:16 1009 hPa 1024 hPa, 2012 1001 hPa, 2009
Maximum Pressure 1004 hPa 00:16 1014 hPa 1029 hPa, 2012 1004 hPa, 2009
Mean Pressure 1002 hPa 1011 hPa 1026 hPa, 2012 1002 hPa, 2009
Mean Wind Speed 5.8 mph (+1.5) 6.1 mph (+1.8) 7.4 mph, 2023 0.9 mph, 2016
Maximum Wind Speed n/a 0.0 mph 16.9, 2023 6.5, 2021
Maximum Gust 27.0 mph 24.0 mph 28.8 mph, 2023 10.3 mph, 2021
Mean Wind Direction n/a
Rainfall 0.0 mm 39.9 mm (122%) 9.8 mm, 2023
Maximum Hourly Rain n/a 01:01 3.4, 2017
Maximum 10-min Rain n/a 00:58 1.6, 2010
Maximum Rain Rate n/a 30, 2010
Minimum Dew Point 10.4 °C 16:14 9.5 °C 13.8 °C, 2019 6.3 °C, 2011
Maximum Dew Point 14.1 °C 00:23 14.8 °C 19.7 °C, 2019 11.4 °C, 2012
Mean Dew Point 12.7 °C 12.2 °C 17.0 °C, 2019 9.4 °C, 2011
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 14.4 °C 13.9 °C 17.5 °C, 2016 10.5 °C, 2011
Day Maximum (09-21) 20.8 °C 22.0 °C 32.7 °C, 2013 18.2 °C, 2023
Max 10m Temp Rise 0.5 °C 13:03 0.7 °C 1.0 °C, 2012 0.5 °C, 2009
Max 1hr Temp Rise 1.5 °C 09:31 1.7 °C 3.5 °C, 2012 1.5 °C, 2009
Max 1hr Hum Rise 5% 17:52 8% 18%, 2015 5%, 2009
Max 10m Temp Fall 0.5 °C 14:27 0.6 °C 1.0 °C, 2015 0.3 °C, 2012
Max 1hr Temp Fall 1.2 °C 23:04 1.4 °C 3.4 °C, 2015 1.2 °C, 2009
Max 1hr Hum Fall 8% 09:12 8% 13%, 2012 6%, 2019
Max 10m Wind Speed 5.2 mph 1.6 mph 13.7 mph, 2023 4.1 mph, 2016
Minimum Feels-like n/a 0.0 °C 21, 2021 11.4, 2011
Maximum Feels-like n/a 0.0 °C 36.9, 2013 21.1, 2023
Mean Feels-like n/a 0.0 °C 28.4, 2013 16.7, 2011
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 6.4 °C (-2.2) 8.1 °C (-0.8) 16.0 °C (+7.4), 2013 4.4 °C (-4.2), 2023
Humidity Range 39% 37% 56%, 2013 22%, 2019
Pressure Range 3 hPa 5 hPa 10 hPa, 2023 2 hPa, 2011
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 4.4 [30%]114 hrs (82%) [35%] 13 [90%], 2021 0 [0%], 2023
Wet Hours 032 hrs (132%) [6%] 10, 2023 0, 2009
Cloud Cover not available
Events None
Comments -
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 22nd July 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

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Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose