It seems that you are using an old list of Synoptic stations where some locations are inaccurate, especially for recycled SYNO numbers for which a Genots have been issued. Please find below few station location errors I caught in eastern Canada. There's probably much more worldwide.
SYNOs 71290, 71272, 71632, 71720 and 71736 are not properly attributed… they belong to stations in Manitoba, British Columbia and Alberta... that’s why you can find a huge discrepancy in Temperatures with surrounding areas on your maps
71632 should be for Lynn Lake, MB (CYYL) not for Britt, ON (WBI)
71272 should be for Tadoule Lake, MB (CYBQ) not for Beausoleil Island, ON
71290 should be for Mackenzie Airport, BC (CYZY) not Upper Rideau Lake, ON
71720 should be for Powell River, BC (CVOP), not Ste Agathe Des Monts, QC
71736 should be for Pincher Creek, AB (CPCK), not Roquemaure, QC
Config list for World SYNOS here seems up to date: http://22.214.171.124/jma/kishou/books/station/station.txt but I suggest you use the one on WMO-OSCAR website (formal list)