Daily Report for 17th January 2021

<<Previous Day
Reset 		Next Day>>
Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 3.2 °C (+0.2) 23:57 0.5 °C (-2.6) 6.6 °C (+3.6), 2014 -5.5 °C (-8.5), 2013
Maximum Temperature 7.1 °C (-0.7) 12:35 5.4 °C (-2.4) 10.6 °C (+2.8), 2020 0.7 °C (-7.1), 2023
Mean Temperature 5.4 °C (-0.3) 3.0 °C (-2.5) 7.6 °C, 2011 -2.0 °C, 2023
Minimum Humidity 77% 15:10 84% 85%, 2011 49%, 2009
Maximum Humidity 91% 23:38 94% 98%, 2010 84%, 2017
Mean Humidity 84% 90% 93%, 2011 68%, 2009
Minimum Pressure 1019 hPa 02:23 1017 hPa 1035 hPa, 2022 987 hPa, 2014
Maximum Pressure 1028 hPa 21:12 1024 hPa 1041 hPa, 2022 993 hPa, 2014
Mean Pressure 1024 hPa 1020 hPa 1038 hPa, 2022 990 hPa, 2014
Mean Wind Speed 5.5 mph (+0.3) 3.7 mph (-1.5) 10.1 mph, 2018 0.5 mph, 2017
Maximum Wind Speed 14.4 mph 06:20 10.9 mph 22.1 mph, 2020 5.8 mph, 2017
Maximum Gust 19.4 mph 06:21 17.2 mph 38.0 mph, 2009 8.4 mph, 2017
Mean Wind Direction NW
Rainfall 0.0 mm 42.3 mm (131%) 16.1 mm, 2011
Maximum Hourly Rain n/a 5, 2009
Maximum 10-min Rain n/a 1.1, 2011
Maximum Rain Rate n/a 15, 2011
Minimum Dew Point 1.7 °C 23:57 -0.9 °C 5.3 °C, 2014 -6.7 °C, 2013
Maximum Dew Point 4.6 °C 00:00 3.8 °C 9.4 °C, 2020 -1.6 °C, 2023
Mean Dew Point 2.9 °C 1.6 °C 6.5 °C, 2011 -3.6 °C, 2023
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 4.2 °C * 08:07 1.4 °C 8.6 °C, 2011 -5.5 °C, 2013
Day Maximum (09-21) 7.1 °C 13:18 5.1 °C 9.0 °C, 2009 0.7 °C, 2023
Max 10m Temp Rise 0.4 °C 10:20 0.3 °C 0.6 °C, 2010 0.1 °C, 2011
Max 1hr Temp Rise 1.2 °C 11:09 1.0 °C 2.4 °C, 2013 0.4 °C, 2011
Max 1hr Hum Rise 3% 18:03 4% 7%, 2018 1%, 2025
Max 10m Temp Fall 0.3 °C 07:18 0.4 °C 0.9 °C, 2019 0.1 °C, 2016
Max 1hr Temp Fall 0.8 °C 18:03 1.2 °C 2.7 °C, 2022 0.3 °C, 2016
Max 1hr Hum Fall 5% 12:43 4% 13%, 2017 2%, 2025
Max 10m Wind Speed 11.3 mph 11:21 8.8 mph 17.1 mph, 2020 4.4 mph, 2017
Minimum Feels-like -0.4 °C 08:00 -3.8 °C 2.8 °C, 2011 -7.6 °C, 2024
Maximum Feels-like 6.6 °C 16:49 5.0 °C 11.6 °C, 2020 0.7 °C, 2023
Mean Feels-like 2.8 °C 0.8 °C 6.7 °C, 2011 -3.2 °C, 2023
Air-frost Hrs 0 hrs 3 hrs 21 hrs, 2023 0 hrs, 2010
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 3.9 °C (-0.9) 4.9 °C (+0.2) 8.5 °C (+3.7), 2012 1.9 °C (-2.9), 2014
Humidity Range 14% 10% 39%, 2009 4%, 2025
Pressure Range 8 hPa 6 hPa 19 hPa, 2010 2 hPa, 2012
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 3.5 [47%]22 hrs (59%) [17%] 7.6 [101%], 2022 0 [0%], 2024
Wet Hours 047 hrs (127%) [11%] 8, 2011 , 2009
Cloud Cover am: Mostly Sunny
pm: Hazy
Events None
Comments -
Extra Comments
Issues no pond temp due to lockdown
Observer Absent? Yes - observations may be unreliable
Pond Temperature @ Hampstead Heath 4.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 17th January 2021.
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

day graph

Webcam Summary of Cloud Conditions

daycamsumFull resolution individual images at up-to 5 minute intervals

Wind rose