Rainfall is heaviest in the northwest and lightest in the southeast and interior. Annual averages on the coast near the Venezuelan border are near , farther east at New Amsterdam, between in southern Guyana's Rupununi Savannah. Areas on the northeast sides of mountains that catch the trade winds average as much as of precipitation annually. Although rain falls throughout the year, about 50 percent of the annual total arrives in the summer rainy season that extends from May to the end of July along the coast and from April through September farther inland. Coastal areas have a second rainy season from November through January. Rain generally falls in heavy afternoon showers or thunderstorms. Overcast days are rare; most days include four to eight hours of sunshine from morning through early afternoon.