Rwanda has a temperate tropical highland climate, with lower temperatures than are typical for equatorial countries because of its high elevation. Kigali, in the centre of the country, has a typical daily temperature range between , with little variation through the year. There are some temperature variations across the country; the mountainous west and north are generally cooler than the lower-lying east. There are two rainy seasons in the year; the first runs from February to June and the second from September to December. These are separated by two dry seasons: the major one from June to September, during which there is often no rain at all, and a shorter and less severe one from December to February. Rainfall varies geographically, with the west and northwest of the country receiving more precipitation annually than the east and southeast. Global warming has caused a change in the pattern of the rainy seasons. According to a report by the Strategic Foresight Group, change in climate has reduced the number of rainy days experienced during a year, but has also caused an increase in frequency of torrential rains. Both changes have caused difficulty for farmers, decreasing their productivity. Strategic Foresight also characterise Rwanda as a fast warming country, with an increase in average temperature of between 0.7 °C to 0.9 °C over fifty years.