The annual precipitation amount in Hungary is 500–750 mm, but there are remarkable differences between different regions.

The spatial distribution of the annual precipitation amount shows double effects. The effects of the altitude and the distance from the Mediterranean Sea are important, but the Atlantic ocean also influences our climate. A hundred meters increase in altitude equals to about 35 mm extra in the annual amount, while the growing distance from the seas means a decrease. The wettest are the southwestern areas of the country and the mountains, where the amount could exceed 800 mm. On average, the low altitude valley of the river Tisza receives the least precipitation, the value does not reach 500 mm. Roughly, the annual sum decreases from SW to NE.

Figure 1.
Average annual precipitation in Hungary based on the 1971–2000 period

Spatial and year-to-year variability is notable in Hungary. The most precipitation falls between May and July, while the least between January and March (Fig. 2.a). Due to a stronger cyclone activity there is a secondary maximum in most parts of the country during the autumn - this is particularly true for Southern Transdanubia. Its temporal uncertainty is shown in the fact that in the wettest years three times as much can fall than in the driest years (Fig. 2.b), and zero precipitation can occur in any month. The country-wide annual precipitation amount showed a decreasing tendency during the last century, the decrease in 109 years was nearly 10 percent.