Pick two weeks. See what the world's weather usually does then — averaged over 30 years.
Data: NASA POWER daily series for 1996–2025, one request per land cell of a 1° grid — air temperature and bias-corrected precipitation from NASA's MERRA-2 reanalysis, radiation from CERES SYN1deg/SRB satellite retrievals. Every value on this map is a 30-year mean for that ISO week: — covered.
Sunshine hours are not measured by satellites directly. They are modelled from the daily clearness index KT — the share of top-of-atmosphere radiation that reaches the ground — as a fraction of the astronomical daylength N: n/N = -0.691 + 4.541·KT − 3.124·KT². The coefficients are fitted against ERA5's own sunshine duration across 22 sites and graded on the half of them the fit never saw: bias -0.21 h/day, RMSE 1.05 h/day. Textbook Ångström–Prescott coefficients score −2.64 / 2.98 on the same test, mostly by drowning the wet tropics.
Read it as climate, not forecast. A fortnight in one particular year can sit far from its 30-year mean. Cells are 1° wide — about 110 km — so a valley and the ridge above it share one number, and small islands inherit the sea around them.