Weather : Intermonsoon weather conditions continued till 15th and Northeast monsoon features appeared thereafter. Heavy rain experienced in the East during the latter part of the month caused floods in the Ampara and Batticaloa districts. A tornado caused considerable damage along a stretch of about one kilometre long and about 300 m wide on 23rd around 1600 hours, at Modara, Colombo.
Rainfall: Distribution of total monthly rainfall and percentage offsets from the 1961-1990 averages are shown in fig. 1. The highest monthly totals reported were
859.6 mm - Natagala Estate (Matara district) 837.0 mm - Mawarella Estate (Matara district)
810.9 mm - Padaviya (Anuradhapura district) 784.8 mm Mutu Iyankaddu ( Mullaitivu district)
766.7 mm - Pottuvil 750.5 mm Mapakadawewa (Badulla district)
722.2 mm - Batticaloa 716.5 mm Alapladniya (Matara district)
713.7 mm - Galoola Estate (Badulla district) 701.6 mm Detanagala Estate (Ratnapura district)
There were no reports of nil rainfall for the month. The lowest rainfalls (below 100 mm) reported were
97.9 mm - Suriyagoda (Kandy district) 67.0 mm - Gawaragiriya (Ratnapura district)
63.0 mm - Aranayaka (Kegalle district) 49.3 mm - Egodagama Ela (Kurunegala district)
There were 15 daily falls of over 125mm of which the highest was 209.2 mm reported from Padaviya on 27th.
Rainfall was above normal in the Northern, Eastern and Uva provinces and in some parts of Northcentral, Central provinces and in some parts of Hambantota, Matara, Kalutara and Ratnapura districts. Rainfall was below normal in the Northwestern province, western parts of the Central province and in parts of Gampaha, Kegalle and Galle districts. Elsewhere it was mostly about normal.
The highest excesses were
453.8 mm – Mapakadawewa (Badulla district) 433.5 mm - Mawarella Estate (Matara district)
372.6 mm - Batticaloa 367.9 mm – Sagamam Tank (Ampara district)
The largest deficits were
308.9 mm – Egodagama Ela (Kurunegala district) 301.0 mm – Waharaka (Kegalle district)
258.7 mm - Dehiowita (Kegalle district) 258.2 mm – Yatiyantota (Kegalle district)
Temperature: Average maximum temperatures were about normal except at Galle where it was little above normal. Average minimum temperatures were little above normal at Bandarawela, Nuwara Eliya and Vavuniya and about normal elsewhere. The highest temperature recorded during the month was 33.8 oC at Katunayaka on the 10th and at Ratmalana on the 24th. The lowest recorded at a coastal station was 22.1 oC at Puttalam on the 25th while that for the whole island was 11.3 oC at Nuwara Eliya on 25th.
Humidity : Average day humidity ranged from 75 % at kurunegala to 89 % at Nuwara Eliya. Average night humidity ranged from 90 % at Hambantota to 98 % at Badulla.
Surface wind : Average surface wind ranged from 1.1 km/h at Kurunegala to 16.5 km/h at Hambantota.
A summary of meteorological data for the month is given in Table 1.
