| | | | | | | | | | | | |
|
| Shannon Airport 1971–2000 averages
|
|
|
|
|
|
|
|
|
|
|
|
| |
| TEMPERATURE (degrees Celsius) | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| mean daily max | 8.6 | 9.0 | 10.7 | 12.9 | 15.7 | 17.9 | 19.8 | 19.6 | 17.4 | 14.0 | 10.9 | 9.2 | 13.8 |
| mean daily min | 3.1 | 3.3 | 4.3 | 5.4 | 7.9 | 10.6 | 12.8 | 12.5 | 10.5 | 8.1 | 5.2 | 4.0 | 7.3 |
| mean temperature | 5.9 | 6.2 | 7.5 | 9.2 | 11.8 | 14.3 | 16.3 | 16.1 | 14.0 | 11.1 | 8.1 | 6.6 | 10.6 |
| absolute max. | 14.8 | 15.0 | 17.9 | 22.2 | 27.2 | 31.6 | 30.6 | 29.8 | 26.1 | 21.6 | 18.2 | 15.2 | 31.6 |
| min. maximum | -1.8 | 0.9 | 3.5 | 5.4 | 8.0 | 11.5 | 13.7 | 13.0 | 11.1 | 7.7 | 2.5 | -0.9 | -1.8 |
| max. minimum | 11.8 | 11.7 | 11.3 | 12.8 | 15.3 | 17.8 | 19.4 | 19.3 | 17.8 | 16.3 | 13.3 | 12.9 | 19.4 |
| absolute min. | -8.2 | -5.5 | -3.9 | -2.2 | 0.3 | 3.4 | 6.1 | 5.7 | 2.5 | -2.0 | -4.8 | -5.8 | -8.2 |
| mean num. of days with air frost | 5.1 | 3.9 | 1.9 | 1.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 2.6 | 3.8 | 18.6 |
| mean num. of days with ground frost | 13.6 | 10.8 | 10.2 | 8.5 | 3.0 | 0.4 | 0.0 | 0.1 | 1.0 | 3.4 | 9.6 | 11.1 | 71.6 |
| mean 5cm soil | 4.1 | 4.1 | 5.6 | 8.3 | 12.0 | 15.4 | 16.7 | 15.7 | 13.3 | 10.2 | 6.6 | 5.2 | 9.8 |
| mean 10cm soil | 4.4 | 4.4 | 5.8 | 8.1 | 11.5 | 14.7 | 16.3 | 15.5 | 13.3 | 10.4 | 6.9 | 5.5 | 9.7 |
| mean 20cm soil | 5.0 | 5.0 | 6.4 | 8.7 | 11.8 | 14.9 | 16.5 | 16.1 | 14.1 | 11.2 | 7.8 | 6.2 | 10.3 |
| RELATIVE HUMIDITY (%) | | | | | | | | | | | | | |
| mean at 0900UTC | 87.1 | 86.8 | 84.8 | 80.5 | 76.8 | 77.4 | 80.2 | 82.5 | 84.6 | 86.9 | 88.2 | 88.0 | 83.7 |
| mean at 1500UTC | 80.5 | 75.5 | 70.6 | 64.5 | 63.0 | 65.6 | 68.0 | 67.8 | 69.3 | 75.7 | 80.3 | 83.1 | 72.0 |
| SUNSHINE (hours) | | | | | | | | | | | | | |
| mean daily duration | 1.6 | 2.2 | 3.0 | 4.8 | 5.7 | 4.9 | 4.3 | 4.4 | 3.8 | 2.7 | 1.9 | 1.3 | 3.4 |
| greatest daily duration | 8.1 | 9.6 | 10.8 | 13.5 | 15.3 | 15.8 | 15.7 | 14.8 | 11.6 | 9.7 | 8.3 | 7.1 | 15.8 |
| mean num. of days with no sun | 9.9 | 7.1 | 5.7 | 2.8 | 1.8 | 1.8 | 2.4 | 2.1 | 3.2 | 5.9 | 8.1 | 11.1 | 62.0 |
| RAINFALL (mm) | | | | | | | | | | | | | |
| mean monthly total | 102.1 | 81.2 | 77.4 | 56.1 | 57.8 | 62.6 | 61.9 | 84.8 | 80.0 | 98.8 | 96.6 | 105.4 | 964.7 |
| greatest daily total | 31.3 | 29.4 | 28.1 | 28.9 | 25.0 | 40.6 | 41.6 | 46.0 | 30.2 | 32.8 | 39.5 | 41.2 | 46.0 |
| mean num. of days with >= 0.2mm | 20 | 17 | 20 | 15 | 16 | 15 | 15 | 17 | 17 | 20 | 19 | 20 | 211 |
| mean num. of days with >= 1.0mm | 16 | 13 | 14 | 11 | 12 | 11 | 11 | 12 | 12 | 16 | 15 | 16 | 159 |
| mean num. of days with >= 5.0mm | 7 | 6 | 5 | 4 | 3 | 4 | 3 | 5 | 5 | 7 | 6 | 7 | 62 |
| WIND (knots) | | | | | | | | | | | | | |
| mean monthly speed | 10.6 | 10.7 | 10.4 | 9.1 | 8.9 | 8.7 | 8.5 | 8.1 | 8.7 | 9.5 | 9.4 | 10.0 | 9.4 |
| max. gust | 82 | 80 | 65 | 62 | 59 | 51 | 52 | 55 | 62 | 71 | 66 | 83 | 83 |
| max. mean 10-minute speed | 55 | 46 | 44 | 40 | 39 | 37 | 33 | 34 | 40 | 47 | 41 | 57 | 57 |
| mean num. of days with gales | 2.0 | 1.0 | 0.9 | 0.3 | 0.2 | 0.1 | 0.0 | 0.0 | 0.2 | 0.6 | 0.7 | 1.5 | 7.5 |
| WEATHER (mean no. of days with..) | | | | | | | | | | | | | |
| snow or sleet | 3.0 | 2.7 | 1.8 | 0.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 1.3 | 9.6 |
| snow lying at 0900UTC | 0.6 | 0.5 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 0.2 | 1.5 |
| hail | 3.9 | 3.6 | 4.3 | 2.3 | 1.5 | 0.2 | 0.1 | 0.2 | 0.4 | 0.8 | 1.7 | 2.9 | 21.8 |
| thunder | 0.9 | 0.4 | 0.4 | 0.4 | 0.4 | 0.6 | 0.8 | 0.5 | 0.3 | 0.4 | 0.5 | 0.6 | 6.1 |
| fog | 3.1 | 1.7 | 1.9 | 2.1 | 1.6 | 1.4 | 1.7 | 2.9 | 3.1 | 3.0 | 3.6 | 3.6 | 29.8 |