Daily Report for 29th December 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 1.5 °C (-1.9) 01:37 1.6 °C (-2.0) 9.7 °C (+6.3), 2015 -2.3 °C (-5.7), 2017
Maximum Temperature 3.8 °C (-4.0) 12:20 6.0 °C (-2.2) 14.6 °C (+6.8), 2021 3.7 °C (-4.1), 2020
Mean Temperature 3.0 °C (-2.9) 3.9 °C (-2.1) 11.0 °C, 2021 1.1 °C, 2014
Minimum Humidity 94% 09:13 83% 98%, 2010 69%, 2011
Maximum Humidity 98% 12:00 97% 98%, 2009 83%, 2011
Mean Humidity 97% 91% 98%, 2010 73%, 2011
Minimum Pressure 991 hPa 22:07 1002 hPa 1037 hPa, 2014 983 hPa, 2020
Maximum Pressure 1001 hPa 00:08 1010 hPa 1042 hPa, 2014 1000 hPa, 2020
Mean Pressure 996 hPa 1006 hPa 1040 hPa, 2014 991 hPa, 2020
Mean Wind Speed 7.1 mph (+2.0) 4.6 mph (-0.5) 10.8 mph, 2012 0.3 mph, 2016
Maximum Wind Speed 16.3 mph 11.0 mph 21.0 mph, 2022 4.4 mph, 2016
Maximum Gust 25.6 mph 13:26 16.7 mph 33.4 mph, 2022 6.3 mph, 2016
Mean Wind Direction E
Rainfall 11.5 mm 70.1 mm (131%) 11.5 mm, 2009
Maximum Hourly Rain 3.2 mm 13:23 4.4 mm, 2017
Maximum 10-min Rain 1.1 mm 13:09 1.9 mm, 2011
Maximum Rain Rate 8 mm/h 16:58 72 mm/h, 2015
Minimum Dew Point 1.2 °C 01:37 0.2 °C 6.6 °C, 2010 -3.3 °C, 2017
Maximum Dew Point 3.5 °C 12:57 5.1 °C 13.0 °C, 2021 1.1 °C, 2014
Mean Dew Point 2.6 °C 2.6 °C 9.3 °C, 2021 -1.1 °C, 2014
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 1.5 °C 2.3 °C 11.2 °C, 2012 -2.3 °C, 2017
Day Maximum (09-21) 3.8 °C 5.8 °C 14.6 °C, 2021 3.7 °C, 2020
Max 10m Temp Rise 0.2 °C 04:04 0.4 °C 0.6 °C, 2016 0.1 °C, 2010
Max 1hr Temp Rise 0.8 °C 04:49 1.0 °C 2.3 °C, 2017 0.4 °C, 2010
Max 1hr Hum Rise 2% 10:38 4% 9%, 2023 0%, 2010
Max 10m Temp Fall 0.1 °C 01:24 0.4 °C 1.7 °C, 2023 0.1 °C, 2009
Max 1hr Temp Fall 0.3 °C 16:25 0.9 °C 2.9 °C, 2023 0.3 °C, 2009
Max 1hr Hum Fall 3% 08:22 5% 11%, 2021 0%, 2010
Max 10m Wind Speed 10.7 mph 10:36 7.9 mph 15.3 mph, 2022 3.4 mph, 2016
Minimum Feels-like -2.9 °C 00:48 -1.6 °C 6.5 °C, 2015 -5.1 °C, 2014
Maximum Feels-like 3.1 °C 22:55 6.2 °C 17.3 °C, 2021 3.1 °C, 2009
Mean Feels-like -0.2 °C 2.5 °C 11.5 °C, 2021 -1.0 °C, 2014
Air-frost Hrs 0 hrs 3 hrs 7 hrs, 2014 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 2.3 °C (-2.1) 4.3 °C (-0.2) 10.2 °C (+5.8), 2017 1.7 °C (-2.8), 2010
Humidity Range 4% 14% 24%, 2017 0%, 2010
Pressure Range 10 hPa 8 hPa 17 hPa, 2017 5 hPa, 2019
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0 [0%]75 hrs (122%) [36%] 7 [100%], 2013 0 [0%], 2009
Wet Hours 11
[Mean rain rate: 1.0 mm/h]
80 hrs (138%) [11%] 11, 2009 0, 2013
Cloud Cover not available
Events None
Comments 10-22 Moderate/Heavy Rain (10-12 Light,17-21 SLight)
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 29th December 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