Daily Report for 9th August 2021

Measure	Value (anomaly)	Time	Month cumul.	Record High	Record Low
Minimum Temperature	13.6 °C (-0.8)	03:22	13.2 °C (-1.3)	17.4 °C (+3.0), 2019	10.7 °C (-3.7), 2023
Maximum Temperature	21.7 °C (-1.3)	14:31	21.1 °C (-2.1)	32.6 °C (+9.6), 2026	15.4 °C (-7.6), 2017
Mean Temperature	16.0 °C (-1.0)		16.6 °C (-1.7)	23.7 °C, 2020	13.9 °C, 2017
Minimum Humidity	61%	14:13	62%	78%, 2017	25%, 2026
Maximum Humidity	94%	09:18	93%	98%, 2023	71%, 2011
Mean Humidity	86%		81%	86%, 2021	45%, 2026
Minimum Pressure	1011 hPa	05:05	1006 hPa	1029 hPa, 2022	999 hPa, 2019
Maximum Pressure	1015 hPa	23:30	1012 hPa	1032 hPa, 2022	1008 hPa, 2019
Mean Pressure	1013 hPa		1009 hPa	1030 hPa, 2022	1002 hPa, 2019
Mean Wind Speed	4.6 mph (+0.6)		4.0 mph (+0.0)	7.9 mph, 2019	1.7 mph, 2022
Maximum Wind Speed	13.8 mph	12:13	12.1 mph	20.5 mph, 2019	7.4 mph, 2012
Maximum Gust	21.7 mph	12:44	18.7 mph	36.9 mph, 2019	8.7 mph, 2012
Mean Wind Direction	n/a		SW	N, 2017	ENE, 2020
Rainfall	9.6 mm		30.7 mm (196%)	39.1 mm, 2017	0.0 mm, 2009
Maximum Hourly Rain	5.0 mm	17:31	1.9 mm	11.2 mm, 2017	1.2 mm, 2013
Maximum 10-min Rain	2.0 mm	16:51	0.9 mm	4.8 mm, 2019	0.8 mm, 2014
Maximum Rain Rate	30 mm/h	16:43	11 mm/h	79 mm/h, 2019	24 mm/h, 2014
Minimum Dew Point	11.6 °C	02:07	11.1 °C	15.2 °C, 2019	3.3 °C, 2016
Maximum Dew Point	15.6 °C	15:48	15.1 °C	20.2 °C, 2020	8.3 °C, 2016
Mean Dew Point	13.5 °C		13.1 °C	17.2 °C, 2020	5.5 °C, 2016
Measure	Value	Time	Month cumul.	Record High	Record Low
Night Minimum (21-09)	13.6 °C	04:48	13.5 °C	18.4 °C, 2019	10.7 °C, 2023
Day Maximum (09-21)	21.7 °C	14:32	21.1 °C	32.6 °C, 2026	15.4 °C, 2017
Max 10m Temp Rise	0.7 °C	12:25	0.7 °C	1.1 °C, 2012	0.2 °C, 2017
Max 1hr Temp Rise	2.4 °C	11:51	2.3 °C	5.0 °C, 2012	0.6 °C, 2018
Max 1hr Hum Rise	13%	17:16	12%	20%, 2019	2%, 2017
Max 10m Temp Fall	1.1 °C	16:48	0.7 °C	1.5 °C, 2019	0.2 °C, 2017
Max 1hr Temp Fall	3.8 °C	17:04	1.9 °C	3.8 °C, 2019	0.8 °C, 2017
Max 1hr Hum Fall	14%	12:00	12%	18%, 2014	1%, 2017
Max 10m Wind Speed	11.0 mph	12:48	9.3 mph	16.4 mph, 2019	4.8 mph, 2009
Minimum Feels-like	15.7 °C	02:29	15.0 °C	21.5 °C, 2019	11.5 °C, 2016
Maximum Feels-like	25.3 °C	14:35	24.5 °C	38.9 °C, 2020	18.3 °C, 2017
Mean Feels-like	19.0 °C		19.5 °C	29.1 °C, 2020	15.7 °C, 2017
Air-frost Hrs	0 hrs		0 hrs	0 hrs, 2009	0 hrs, 2009
Minimum PM2.5	n/a		0.0 µg/m³	3.6 µg/m³, 2026	0.0 µg/m³, 2009
Maximum PM2.5	n/a		0.0 µg/m³	18.5 µg/m³, 2026	18.5 µg/m³, 2026
Mean PM2.5	n/a		0.0 µg/m³	8.1 µg/m³, 2026	8.1 µg/m³, 2026
Measure	Value (anomaly)		Month cumul.	Record High	Record Low
Temperature Range	8.1 °C (-0.5)		7.9 °C	19.0 °C, 2026	2.3 °C, 2017
Humidity Range	33%		31%	57%, 2012	8%, 2017
Pressure Range	5 hPa		6 hPa	13 hPa, 2017	3 hPa, 2022

Observation	Detail
Sun Hours	2 hrs [15%]
Wet Hours	7 hrs
Cloud Cover	am: Overcast pm: Partly Cloudy transitioned to Mostly Cloudy
Events	None
Comments	rn
Observer Absent?	Yes - observations may be unreliable
Pond Temperature	18.5 °C

Notes: Detailed daily weather report for Hampstead, NW3, London on 9th August 2021. Times of extremes use the midpoint of the longest continuous period at that value. Cumulative anomalies are relative to the expected value for the month-to-date. Sun and wet hours are derived from webcam/rainfall analysis and may be adjusted. Data should be viewed with appropriate caution.

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Daily Graph of Conditions

Wind direction

Air pollution

Wind rose

Webcam Summary of Cloud Conditions

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