Daily Report for 7th July 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 13.8 °C (+0.1) 05:31 15.4 °C (+1.9) 18.8 °C (+5.1), 2017 9.4 °C (-4.3), 2020
Maximum Temperature 18.0 °C (-4.8) 14:51 24.6 °C (+2.0) 30.3 °C (+7.6), 2018 17.8 °C (-4.9), 2024
Mean Temperature 15.2 °C (-2.3) 19.1 °C (+1.9) 24.3 °C, 2018 14.2 °C, 2024
Minimum Humidity 75% 10:56 48% 75%, 2009 32%, 2017
Maximum Humidity 93% 13:04 87% 94%, 2019 68%, 2016
Mean Humidity 88% 71% 88%, 2009 52%, 2017
Minimum Pressure 1002 hPa 05:54 1010 hPa 1030 hPa, 2013 1002 hPa, 2009
Maximum Pressure 1008 hPa 23:24 1015 hPa 1033 hPa, 2022 1005 hPa, 2011
Mean Pressure 1005 hPa 1012 hPa 1031 hPa, 2013 1004 hPa, 2011
Mean Wind Speed 4.0 mph (-0.3) 5.4 mph (+1.1) 7.7 mph, 2011 2.4 mph, 2018
Maximum Wind Speed n/a 0.0 mph 18.1, 2015 9.8, 2013
Maximum Gust 19.0 mph 23.3 mph 28.4 mph, 2015 13.0 mph, 2014
Mean Wind Direction n/a
Rainfall 7.1 mm 12.1 mm (116%) 7.1 mm, 2009
Maximum Hourly Rain 2.7 mm 15:43 4.4 mm, 2024
Maximum 10-min Rain 1.7 mm 17:39 1.7 mm, 2009
Maximum Rain Rate 33 mm/h 13:33 33 mm/h, 2009
Minimum Dew Point 11.9 °C 00:07 10.2 °C 11.9 °C, 2009 4.7 °C, 2015
Maximum Dew Point 15.5 °C 14:56 16.3 °C 17.5 °C, 2018 11.1 °C, 2014
Mean Dew Point 13.3 °C 13.3 °C 15.0 °C, 2018 9.4 °C, 2014
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 13.8 °C 15.4 °C 18.8 °C, 2017 9.4 °C, 2020
Day Maximum (09-21) 18.0 °C 24.6 °C 30.3 °C, 2018 17.8 °C, 2024
Max 10m Temp Rise n/a 15:25 0.6 °C 0.9, 2023 0.5, 2015
Max 1hr Temp Rise n/a 10:16 2.1 °C 4.2, 2023 1.5, 2021
Max 1hr Hum Rise n/a 14:25 7% 22, 2020 5, 2021
Max 10m Temp Fall n/a 15:35 0.5 °C 1.9, 2024 0.3, 2010
Max 1hr Temp Fall n/a 15:49 1.3 °C 4.2, 2024 1.2, 2010
Max 1hr Hum Fall n/a 09:32 9% 17, 2023 7, 2010
Max 10m Wind Speed n/a 0.0 mph 15, 2015 7.4, 2017
Minimum Feels-like n/a 0.0 °C 21.9, 2017 8, 2020
Maximum Feels-like n/a 0.0 °C 34.2, 2018 20.3, 2024
Mean Feels-like n/a 0.0 °C 28.3, 2018 16.1, 2024
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 4.2 °C (-4.9) 9.2 °C (+0.2) 18.8 °C (+9.7), 2023 4.2 °C (-4.9), 2009
Humidity Range 18% 39% 54%, 2018 18%, 2009
Pressure Range 6 hPa 5 hPa 10 hPa, 2021 2 hPa, 2018
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 2.9 [19%]48 hrs (107%) [46%] 14.5 [97%], 2023 1 [7%], 2012
Wet Hours 3
[Mean rain rate: 2.4 mm/h]
5.1 hrs (66%) [3%] 5, 2020 0, 2010
Cloud Cover not available
Events None
Comments Moderate-Torrential 02,11,13,15-16,1730+ Rain/Showers
Extra Comments
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 7th 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

daygraph daygraph 2 daygraph-wdir

Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose