Along the coast and in the off shore islands of Tanzania, the average temperature ranges between 27°C and 29°C, while in the central, northern and western parts temperatures range between 20°C and 30°C. Temperatures are higher between December and March, and coolest between June and July. The long rains begin in March and end in May, while the short rains begin in October and continues to early December. In general, annual rainfall varies from 550 mm in the central part of the country up to 3690 mm in some parts of south-western highlands.
- Trend analysis results for the period 1961 – 2013 show a statistically significant increasing trend in mean annual maximum and minimum temperature throughout the country.
- Trend in mean annual minimum temperature is much faster as compared to the trend in mean annual maximum temperature.
- Results from trend analysis on mean annual rainfall time-series indicate a slightly declining trend in most of the stations. However, the observed trends are not statistically significant.