Daily Report for 1st August 2009

<<Previous Day
Reset
Next Day>>
Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 15.1 °C (+0.5) 23:55 15.1 °C (+0.5) 16.9 °C (+2.3), 2020 8.9 °C (-5.7), 2015
Maximum Temperature 20.2 °C (-3.1) 14:13 20.2 °C (-3.1) 32.8 °C (+9.5), 2013 19.0 °C (-4.3), 2016
Mean Temperature 17.6 °C (-1.3) 17.6 °C (-1.3) 25.5 °C, 2013 15.8 °C, 2016
Minimum Humidity 56% 00:26 56% 67%, 2021 31%, 2013
Maximum Humidity 91% 23:37 91% 93%, 2012 69%, 2011
Mean Humidity 74% 74% 82%, 2021 51%, 2011
Minimum Pressure 1006 hPa 17:49 1006 hPa 1020 hPa, 2018 998 hPa, 2023
Maximum Pressure 1014 hPa 00:38 1014 hPa 1023 hPa, 2018 1004 hPa, 2023
Mean Pressure 1010 hPa 1010 hPa 1022 hPa, 2018 1003 hPa, 2023
Mean Wind Speed 4.7 mph (+0.7) 4.7 mph (+0.7) 6.8 mph, 2023 1.6 mph, 2022
Maximum Wind Speed n/a 0.0 mph 15.6, 2016 8.1, 2021
Maximum Gust 19.0 mph 19.0 mph 22.6 mph, 2016 12.5 mph, 2021
Mean Wind Direction n/a
Rainfall 0.3 mm 0.3 mm (17%) 4.6 mm, 2016
Maximum Hourly Rain 0.3 mm 18:06 1.7 mm, 2016
Maximum 10-min Rain 0.3 mm 18:06 0.5 mm, 2021
Maximum Rain Rate n/a 2.7, 2016
Minimum Dew Point 8.4 °C 00:26 8.4 °C 14.5 °C, 2022 4.3 °C, 2015
Maximum Dew Point 16.3 °C 18:36 16.3 °C 18.5 °C, 2013 9.7 °C, 2015
Mean Dew Point 12.8 °C 12.8 °C 16.0 °C, 2013 7.0 °C, 2015
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 15.5 °C * 15.5 °C 16.9 °C, 2020 8.9 °C, 2015
Day Maximum (09-21) 20.2 °C 20.2 °C 32.8 °C, 2013 19.0 °C, 2016
Max 10m Temp Rise 0.4 °C 10:37 0.4 °C 1.0 °C, 2015 0.3 °C, 2016
Max 1hr Temp Rise 1.1 °C 08:19 1.1 °C 3.8 °C, 2018 1.1 °C, 2009
Max 1hr Hum Rise 9% 17:46 9% 16%, 2012 6%, 2010
Max 10m Temp Fall 0.5 °C 20:03 0.5 °C 1.0 °C, 2017 0.3 °C, 2014
Max 1hr Temp Fall 2.0 °C 20:22 2.0 °C 2.6 °C, 2015 1.1 °C, 2010
Max 1hr Hum Fall 6% 09:10 6% 21%, 2018 6%, 2009
Max 10m Wind Speed 3.3 mph 3.3 mph 12.2 mph, 2016 3.3 mph, 2009
Minimum Feels-like n/a 0.0 °C 20.6, 2022 8.2, 2015
Maximum Feels-like n/a 0.0 °C 37.4, 2013 20.3, 2016
Mean Feels-like n/a 0.0 °C 30.1, 2013 16.8, 2015
Air-frost Hrs 0 hrs 0 hrs 0 hrs, 2009 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 5.1 °C (-3.6) 5.1 °C (-3.6) 16.2 °C (+7.5), 2013 5.1 °C (-3.6), 2009
Humidity Range 35% 35% 60%, 2013 24%, 2021
Pressure Range 8 hPa 8 hPa 11 hPa, 2013 2 hPa, 2010
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0.3 [2%]0.3 hrs (5%) [2.1%] 13 [92%], 2013 0 [0%], 2016
Wet Hours 11 hrs (82%) [4.2%] 8, 2016 0, 2010
Cloud Cover not available
Events None
Comments SLight/Light 15-18 occasional., Moderate 19 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 1st August 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