Weather in South London during April 2011
Record-breaking warm April and also extremely dry.
Temperatures
The average maximum temperature during April 2011 was 19.3 Celsius (67F), and that was 4.9 Celsius (9F) above the 20-year average and 6.1 Celsius (11F) above the 100-year normal. The average minimum temperature was 7.9 Celsius (46F), and that was 2.5 Celsius (4.5F) above the 20-year normal but 3.2 Celsius (6F), above the 100-year average. This was the warmest April since instrument records were standardized in the 19th century, thus eclipsing the remarkable 2007 April record by 0.6 Celsius (1F) which in itself was 1.4 Celsius (2.5F) warmer than the previous record set in 1943.
The highest temperature recorded during April was 27.2 Celsius (81F) on the 23rd. This was the warmest April day since the 16th in 1949, and perhaps since records began as the highest temperatures on that day appeared to be confined to central and north London. The temperature exceeded 25 Celsius (77F) on each day between the 20th and 23rd, with maxima also exceeding 20 Celsius (68F) on 8 other days. There were no cold days during April. and there were only 4 days when the temperature was below average. On the 5th, the maximum was only 12.4 Celsius (54F) but this was 1.4 Celsius (2.5F) higher than the previous lowest maximum set in 2002.
There were no outstandingly mild nights during April. However, on 6 nights minimum temperatures remained above 10 Celsius (50F). The mildest night was the 1st/2nd with a low of 12.0 Celsius (54F). Generally, the coolest nights occurred in the first half of the month, but there were only 3 nights when the temperature dipped below 5 Celsius (41F). On the night of the 2nd/3rd a minimum of 3.4 Celsius (38F) occurred, but the coldest night was the 12th/13th with a low of 3.1 Celsius (37F). This was substantially higher than any other 'coldest April night' at this site in records dating back to 1989. The previous highest was 0.9 Celsius (33F) in 2001.
Frost
For the third consecutive April there were no air frosts. There were only 2 grass frosts. The night of the 2nd/3rd had a grass minimum of minus 0.3 Celsius (32F) and the night of the 12th/13th had a reading of minus 0.6 Celsius (31F). The 2 grass frosts were a record low for this site (1989) with the record (6) occurring in April 1995.
Rain
A total of 2.6 millimetres (0.1 ins) of rain fell during April and that was only 5% of the 20-year average. It was the driest April since records began (1989) at this site, just beating the previous record (2.8 millimetres) set in 2007. It was probably the driest April in this area since 1938 and also the driest early Spring (March and April combined) since 1938. Measurable rain only fell on 3 days. There was 1.3 millimetres the 4th, 1.0 millimetres on the 23rd, although some areas close by to the north and east had substantially more, and the 29th with a mere 0.3 millimetres..
Thunderstorms
The first thunderstorm in this area since November 14th occurred on the late afternoon and early evening of the 23rd. Although thunder and lightning were frequent through the 2 hours 20 minutes duration, the active cells stubbornly remained to the north and east of this site.
Hail
No hail was observed.
Snow
No sleet or snow occurred.
Wind
The first half of April was dominated by gentle, occasionally moderate, winds mainly from between southwest and northwest,. There were 6 days when gusts exceeded 20 knots (23mph), including a gust of 25 knots (29mph) on the 5th. After mid month the breeze was predominantly from the northeast. Winds were mostly light or gentle with the 30th the only day with a gust above 20 knots (23mph).
Fog
No fog was observed in this area.
Monthly figures for April in, and around, London
The average maximum temperature during April 2011 was 19.3 Celsius (67F), and that was 4.9 Celsius (9F) above the 20-year average and 6.1 Celsius (11F) above the 100-year normal. The average minimum temperature was 7.9 Celsius (46F), and that was 2.5 Celsius (4.5F) above the 20-year normal but 3.2 Celsius (6F), above the 100-year average. This was the warmest April since instrument records were standardized in the 19th century, thus eclipsing the remarkable 2007 April record by 0.6 Celsius (1F) which in itself was 1.4 Celsius (2.5F) warmer than the previous record set in 1943.
The highest temperature recorded during April was 27.2 Celsius (81F) on the 23rd. This was the warmest April day since the 16th in 1949, and perhaps since records began as the highest temperatures on that day appeared to be confined to central and north London. The temperature exceeded 25 Celsius (77F) on each day between the 20th and 23rd, with maxima also exceeding 20 Celsius (68F) on 8 other days. There were no cold days during April. and there were only 4 days when the temperature was below average. On the 5th, the maximum was only 12.4 Celsius (54F) but this was 1.4 Celsius (2.5F) higher than the previous lowest maximum set in 2002.
There were no outstandingly mild nights during April. However, on 6 nights minimum temperatures remained above 10 Celsius (50F). The mildest night was the 1st/2nd with a low of 12.0 Celsius (54F). Generally, the coolest nights occurred in the first half of the month, but there were only 3 nights when the temperature dipped below 5 Celsius (41F). On the night of the 2nd/3rd a minimum of 3.4 Celsius (38F) occurred, but the coldest night was the 12th/13th with a low of 3.1 Celsius (37F). This was substantially higher than any other 'coldest April night' at this site in records dating back to 1989. The previous highest was 0.9 Celsius (33F) in 2001.
Frost
For the third consecutive April there were no air frosts. There were only 2 grass frosts. The night of the 2nd/3rd had a grass minimum of minus 0.3 Celsius (32F) and the night of the 12th/13th had a reading of minus 0.6 Celsius (31F). The 2 grass frosts were a record low for this site (1989) with the record (6) occurring in April 1995.
Rain
A total of 2.6 millimetres (0.1 ins) of rain fell during April and that was only 5% of the 20-year average. It was the driest April since records began (1989) at this site, just beating the previous record (2.8 millimetres) set in 2007. It was probably the driest April in this area since 1938 and also the driest early Spring (March and April combined) since 1938. Measurable rain only fell on 3 days. There was 1.3 millimetres the 4th, 1.0 millimetres on the 23rd, although some areas close by to the north and east had substantially more, and the 29th with a mere 0.3 millimetres..
Thunderstorms
The first thunderstorm in this area since November 14th occurred on the late afternoon and early evening of the 23rd. Although thunder and lightning were frequent through the 2 hours 20 minutes duration, the active cells stubbornly remained to the north and east of this site.
Hail
No hail was observed.
Snow
No sleet or snow occurred.
Wind
The first half of April was dominated by gentle, occasionally moderate, winds mainly from between southwest and northwest,. There were 6 days when gusts exceeded 20 knots (23mph), including a gust of 25 knots (29mph) on the 5th. After mid month the breeze was predominantly from the northeast. Winds were mostly light or gentle with the 30th the only day with a gust above 20 knots (23mph).
Fog
No fog was observed in this area.
Monthly figures for April in, and around, London
| Place | Maximum | Minimum | Rainfall (mm) |
| Central London | 27.1 | 5.8 | 3 |
| Heathrow A/P | 27.4 | 4.6 | 2 |
| Gatwick A/P | 27.3 | 0.2 | 1 |
| Croydon | 25,9 | 3.9 | 1 |
| Northolt | 27.4 | 1.2 | 4 |
| Farnborough | 26.0 | 1.5 | 0.4 |
| Stansted A/P | 26.3 | 1.0 | 3 |
