Daytime high temperatures in the Sarnia area have been about five degrees above normal this month, according to Environment Canada.
Warning Preparedness Meteorologist Geoff Coulson said this week's forecast looks like a continuation of the trend the area has seen for much of the month.
"The jet stream, which tends to act as the boundary between the really cold arctic air to the north and the milder air to the south, that jet stream has consistently been more over northern Ontario and even points further north, keeping southwestern Ontario, generally, in this milder than normal air mass."
Coulson said while January tends to be one of the colder months in southwestern Ontario, he said the area has seen an average temperature of 1 C, 34 F.
"And the average temperature long-term for the month of January is normally -4.8 C so we've been well above that so far this month."
Coulson said at night, lows have been around or just below the freezing mark.
"So for this time of year, normal overnight lows should be about -8 C. Again, looking at the numbers so far this month, we've only had really a couple of days, and it's been the most recent ones, the 14th and 15th of January dipping down to about -9 C, -10 C."
Tuesday's forecast was calling for a high of 8 C, 46 F in the afternoon and a night time low of 3 C, 37 F.
"And really, looking forward into the rest of the work-week, at least in through Thursday, those daytime highs continue to be above the freezing mark," said Coulson. "And then we finally get a little colder as we get into Friday and Saturday but still somewhat above the long-term seasonal values."
Coulson said despite the warmer weather, the area won't be setting any record high temperatures on Tuesday.
"We did have a site operating in the Sarnia area from 1927 to 1961, and on January 17 it actually got up to 13.9 C back in 1952."
