Weather in South London during November 2009
Extremely wet - The second wettest November, behind 1940, for at least 110 years; and the second wettest of all months at this site (started 1988) behind October 2000. A very mild November - Only the Novembers of 1938 and 1994 have been milder during the last 110 years.
Temperatures
The average maximum temperature during November 2009 was 12.3 Celsius (54F), and that was 1.3 Celsius (2F) above the 20-year normal, but 2.1 degrees Celsius (4F) above the 100-year normal. The average minimum temperature was 7.3 Celsius (45F), and that was 2.3 Celsius (4F) above the 20-year average, and 3.4 Celsius (6F)above the 100-year normal.
The highest temperature recorded during November was 16.8 Celsius (62F) on the 1st, but the temperature also rose above 16 Celsius (61F) on the 21st. A short rather cold interlude occurred at the beginning of the second week, and on the 9th the maximum temperature was only 8.0 Celsius (46F). The following day was only fractionally milder, but between the 12th and 25th highs were generally between 12 and 15 Celsius (54-59F). The last 4 days of the month were colder, and after a high of only 7.6 Celsius (46F) on the 29th, the maximum on the 30th failed to rise above 6.4 Celsius (43F).
There were 2 very mild nights during November, the 18th/19th and the following night both with minimum temperatures of 12.8 Celsius (55F). On 2 other nights, the 12th/13th and 17th/18th temperatures remained above 10 Celsius (50F). Unusually, temperatures only fell below 5 Celsius (41F) on 4 nights, with all of these lower figures occurring between the 4th and 10th of the month. The lowest value, 1.0 Celsius (34F), was recorded on the night of the 8th/9th, but the following night was only 0.1 Celsius milder.
Frost
There were no air frosts during November but grass frosts occurred on the nights of the 6th/7th, 8th/9th, and on the following night when the temperature fell to minus 3.4 Celsius (26F).
Rain
A staggering 161.2 millimetres (6.3 ins.) of rain fell in November, more than 2.5 times the monthly average. There were only 2 completely dry days, although there were 5 other days with negligible rainfall. Wet days (1.0mm/0.04 ins, or more) numbered 19, and that was 9 days above average. The heaviest rain occurred in 2 clusters. The 4 days from the 12th to 15th produced 68 millimetres (2.7 ins.) of rain including 27.9 millimetres (1.1 ins.) on the 13th, and 24.1 millimetres on the following day. Another 19 millimetres fell in the 48-hour period covering the 21st and 22nd, and then on the 28th and 29th a total of 40 millimetres (1.6 ins.) was measured.
Thunderstorms
There were rumbles of thunder on the morning of the 14th, with further thunder and lightning before dawn on the 16th. One clap of thunder occurred early on the afternoon of the 29th. This made it the thunderiest November in south London since records began in 1988.
Hail
No hail was observed in this part of South London.
Snow
None reported.
Wind
Gentle or moderate winds from between southwest and southeast predominated during November. However, breezes were light at times during the first 11 days of the month, and fresh at times at the end of the second week and during the fourth week. A gust of 37 knots (42mph) occurred on the 25th.
Fog
Dense fog occurred early on the 9th, but it had cleared from this part of London by mid morning.
Monthly figures for November in, and around, London
The average maximum temperature during November 2009 was 12.3 Celsius (54F), and that was 1.3 Celsius (2F) above the 20-year normal, but 2.1 degrees Celsius (4F) above the 100-year normal. The average minimum temperature was 7.3 Celsius (45F), and that was 2.3 Celsius (4F) above the 20-year average, and 3.4 Celsius (6F)above the 100-year normal.
The highest temperature recorded during November was 16.8 Celsius (62F) on the 1st, but the temperature also rose above 16 Celsius (61F) on the 21st. A short rather cold interlude occurred at the beginning of the second week, and on the 9th the maximum temperature was only 8.0 Celsius (46F). The following day was only fractionally milder, but between the 12th and 25th highs were generally between 12 and 15 Celsius (54-59F). The last 4 days of the month were colder, and after a high of only 7.6 Celsius (46F) on the 29th, the maximum on the 30th failed to rise above 6.4 Celsius (43F).
There were 2 very mild nights during November, the 18th/19th and the following night both with minimum temperatures of 12.8 Celsius (55F). On 2 other nights, the 12th/13th and 17th/18th temperatures remained above 10 Celsius (50F). Unusually, temperatures only fell below 5 Celsius (41F) on 4 nights, with all of these lower figures occurring between the 4th and 10th of the month. The lowest value, 1.0 Celsius (34F), was recorded on the night of the 8th/9th, but the following night was only 0.1 Celsius milder.
Frost
There were no air frosts during November but grass frosts occurred on the nights of the 6th/7th, 8th/9th, and on the following night when the temperature fell to minus 3.4 Celsius (26F).
Rain
A staggering 161.2 millimetres (6.3 ins.) of rain fell in November, more than 2.5 times the monthly average. There were only 2 completely dry days, although there were 5 other days with negligible rainfall. Wet days (1.0mm/0.04 ins, or more) numbered 19, and that was 9 days above average. The heaviest rain occurred in 2 clusters. The 4 days from the 12th to 15th produced 68 millimetres (2.7 ins.) of rain including 27.9 millimetres (1.1 ins.) on the 13th, and 24.1 millimetres on the following day. Another 19 millimetres fell in the 48-hour period covering the 21st and 22nd, and then on the 28th and 29th a total of 40 millimetres (1.6 ins.) was measured.
Thunderstorms
There were rumbles of thunder on the morning of the 14th, with further thunder and lightning before dawn on the 16th. One clap of thunder occurred early on the afternoon of the 29th. This made it the thunderiest November in south London since records began in 1988.
Hail
No hail was observed in this part of South London.
Snow
None reported.
Wind
Gentle or moderate winds from between southwest and southeast predominated during November. However, breezes were light at times during the first 11 days of the month, and fresh at times at the end of the second week and during the fourth week. A gust of 37 knots (42mph) occurred on the 25th.
Fog
Dense fog occurred early on the 9th, but it had cleared from this part of London by mid morning.
Monthly figures for November in, and around, London
| Place | Maximum | Minimum | Rainfall (mm) |
| C. London | 17.4 | 4.6 | 135 |
| Heathrow A/P | 17.4 | 2.7 | 147 |
| Gatwick A/P | 16.2 | -1.5 | 203 |
| Croydon | 15.9 | 1.3 | 190 |
| Northolt | 17.1 | -0.6 | 148 |
| Farnborough | 16.9 | -0.1 | 171 |
| Stansted A/P | 16.4 | 1.7 | 116 |