diff --git simworld.cc simworld.cc
index 3176470428..f6d7388380 100644
--- simworld.cc
+++ simworld.cc
@@ -6026,7 +6026,7 @@ void karte_t::calc_climate_map_region( sint16 xtop, sint16 ytop, sint16 xbottom,
 	const sint16 max_patchsize_x = clamp( 5, xbottom / 24, 256 );
 	const sint16 max_patchsize_y = clamp( 5, ybottom / 24, 256 );
 
-	minivec_tpl<uint8> allowed( 8 );
+	minivec_tpl<uint8> allowed( MAX_CLIMATES );
 	{
 		// find the next climateless tile
 		for(  sint16 y = ytop;  y < ybottom;  y++  ) {
@@ -6040,7 +6040,7 @@ void karte_t::calc_climate_map_region( sint16 xtop, sint16 ytop, sint16 xbottom,
 							allowed.append(cl);
 						}
 					}
-					climate cl = (climate)allowed[ simrand( allowed.get_count() - 1 ) ];
+					climate cl = (!allowed.empty()) ? (climate)allowed[ simrand( allowed.get_count() - 1 ) ] : desert_climate;
 					// now we do an ellipse with size wx and wy around the starting point
 					const sint32 wx = simrand( max_patchsize_x );
 					const sint32 wy = simrand( max_patchsize_y );