diff --git a/R/WeightedMean.R b/R/WeightedMean.R
index 70c33b465e7567538774c4f6e08a2404965e38c7..2ab1a1a94a252ced4d88a684003807a9c6c9fe77 100644
--- a/R/WeightedMean.R
+++ b/R/WeightedMean.R
@@ -120,7 +120,8 @@ WeightedMean <- function(data, lon, lat, region = NULL, mask = NULL, londim = NU
   cosphi <- t(array(cos(lat * pi / 180), dim = c(length(lat), length(lon))))
   nblat <- length(lat)
   nblon <- length(lon)
-  dlon <- abs(c(lon[2 : nblon] - lon[1 : nblon - 1])) * pi / 180
+  lon[lon > 180] = lon[lon > 180] - 360
+  dlon <- abs(c(abs(lon[2 : nblon]) - abs(lon[1 : nblon - 1]))) * pi / 180
   dlon <- c(dlon, dlon[1])
   dlon <- array(dlon, dim = c(nblon, nblat))
   dlat <- abs(c(lat[2 : nblat] - lat[1 : nblat - 1])) * pi / 180