Daily Report for 27th July 2018

Measure	Value (anomaly)	Time	Month cumul.	Record High	Record Low
Minimum Temperature	19.3 °C (+4.6)	06:06	15.8 °C (+1.6)	19.3 °C (+4.6), 2018	12.4 °C (-2.3), 2009
Maximum Temperature	31.8 °C (+8.5)	15:34	27.9 °C (+4.9)	31.8 °C (+8.5), 2018	19.7 °C (-3.6), 2015
Mean Temperature	24.5 °C (+6.5)		22.1 °C (+3.3)	24.5 °C, 2018	16.2 °C, 2009
Minimum Humidity	41%	13:38	39%	83%, 2023	36%, 2013
Maximum Humidity	83%	19:05	85%	96%, 2023	76%, 2026
Mean Humidity	63%		61%	90%, 2023	56%, 2026
Minimum Pressure	1007 hPa	17:51	1017 hPa	1020 hPa, 2022	996 hPa, 2015
Maximum Pressure	1014 hPa	00:00	1020 hPa	1023 hPa, 2022	1004 hPa, 2015
Mean Pressure	1010 hPa		1018 hPa	1022 hPa, 2022	1000 hPa, 2015
Mean Wind Speed	2.8 mph (-1.5)		3.1 mph (-1.2)	8.7 mph, 2015	2.0 mph, 2012
Maximum Wind Speed	15.2 mph	18:08	10.5 mph	19.0 mph, 2015	7.4 mph, 2014
Maximum Gust	20.7 mph	16:58	16.1 mph	31.1 mph, 2020	10.7 mph, 2014
Mean Wind Direction	n/a		SSE	NW, 2014	N, 2011
Rainfall	7.3 mm		25.7 mm (64%)	11.0 mm, 2019	0.0 mm, 2011
Maximum Hourly Rain	5.9 mm	18:38	0.8 mm	5.9 mm, 2018	0.2 mm, 2015
Maximum 10-min Rain	5.1 mm	18:16	0.4 mm	5.1 mm, 2018	0.2 mm, 2015
Maximum Rain Rate	66 mm/h	18:11	4.1 mm/h	66 mm/h, 2018	0.8 mm/h, 2023
Minimum Dew Point	15.1 °C	05:27	10.9 °C	15.1 °C, 2018	7.4 °C, 2009
Maximum Dew Point	20.9 °C	16:30	15.9 °C	20.9 °C, 2018	12.9 °C, 2011
Mean Dew Point	16.6 °C		13.5 °C	17.1 °C, 2023	11.0 °C, 2025
Measure	Value	Time	Month cumul.	Record High	Record Low
Night Minimum (21-09)	19.3 °C	06:06	15.8 °C	19.3 °C, 2018	12.4 °C, 2009
Day Maximum (09-21)	31.8 °C	15:34	27.9 °C	31.8 °C, 2018	19.2 °C, 2019
Max 10m Temp Rise	0.7 °C	07:04	0.7 °C	0.8 °C, 2017	0.2 °C, 2019
Max 1hr Temp Rise	3.4 °C	07:48	2.7 °C	3.4 °C, 2018	0.8 °C, 2019
Max 1hr Hum Rise	20%	17:11	13%	20%, 2018	3%, 2023
Max 10m Temp Fall	1.4 °C	16:33	0.6 °C	1.4 °C, 2018	0.3 °C, 2015
Max 1hr Temp Fall	5.0 °C	17:03	2.3 °C	5.0 °C, 2018	0.8 °C, 2023
Max 1hr Hum Fall	16%	07:51	12%	16%, 2018	5%, 2019
Max 10m Wind Speed	10.4 mph	16:57	7.7 mph	14.0 mph, 2015	3.9 mph, 2009
Minimum Feels-like	23.4 °C	05:45	18.4 °C	23.4 °C, 2018	14.2 °C, 2024
Maximum Feels-like	37.8 °C	15:39	31.3 °C	37.8 °C, 2018	22.6 °C, 2011
Mean Feels-like	29.5 °C		25.2 °C	29.5 °C, 2018	18.8 °C, 2015
Air-frost Hrs	0 hrs		0 hrs	0 hrs, 2009	0 hrs, 2009
Minimum PM2.5	n/a		0.0 µg/m³	0.7 µg/m³, 2026	0.0 µg/m³, 2009
Maximum PM2.5	n/a		0.0 µg/m³	9.1 µg/m³, 2026	9.1 µg/m³, 2026
Mean PM2.5	n/a		0.0 µg/m³	3.1 µg/m³, 2026	3.1 µg/m³, 2026
Measure	Value (anomaly)		Month cumul.	Record High	Record Low
Temperature Range	12.5 °C (+3.9)		12.1 °C	14.2 °C, 2013	4.4 °C, 2020
Humidity Range	42%		46%	54%, 2013	13%, 2020
Pressure Range	6 hPa		4 hPa	14 hPa, 2024	2 hPa, 2010

Observation	Detail
Sun Hours	8 hrs [56%]
Wet Hours	2 hrs
Cloud Cover	am: Sunny pm: Mostly Cloudy
Events	Moderate Thunderstorm
Comments	pm Shs & H T-S
Observer Absent?	Yes - observations may be unreliable
Pond Temperature	0.0 °C

Notes: Detailed daily weather report for Hampstead, NW3, London on 27th July 2018. 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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