Frost-free season ends in Greater Moncton

Frost covers a maple leaf (Twitter)

A light, scattered frost appeared in Greater Moncton this morning with a chilly record-breaking low temperature of -1.3°C.

Unofficially this is a record low for 20 September and it also means the frost-free period – which on average lasts 134 days – is now over.

While 04 October is the average first fall frost date, Environment Canada notes how there’s a 33 percent chance it can occur before 21 September.

The frost-free period was much shorter in 2020 at only 102 days thanks to a late spring frost on 10 June when the thermometer dropped to -0.6°C.

UPDATE – Numerous record lows were broken early Monday morning including: -Greater Moncton broke record of -1.1°C set in 1904. -Edmundston dropped to -6.2°C which broke record of -3.0°C from 1986.

February 2020 – Cold yet above normal

Ducks on ice, Irishtown Nature Park, Moncton, 29 Feb 2020 (Dearing)

Some of the coldest lows yet this winter were recorded in February yet the mean monthly temperature in Greater Moncton was actually above normal based on the 30-year average.

Four overnight lows dropped to -20°C or lower with a frigid -24.4°C on 15 Feb which was the coldest minimum in five years (since February 2015).

Eleven days were below freezing but daytime highs climbed above freezing during the final week of the month.

Three major storms brought above normal snowfall but a scant 1.0 mm of rain was recorded which was well below the average of 28 mm.

FEBRUARY 2020 ALMANAC (at Greater Moncton Int’l Airport, 1981-2010)

Average HIGH -1.0°C

Average LOW -11.4°C

AVERAGE -6.2°C (about 1.4 degrees ABOVE normal)

Extreme HIGH 7.3°C (24 Feb)

Extreme LOW -24.4°C (15 Feb)

RAINFALL 1.0 mm (substantially BELOW normal)

SNOWFALL 71.2 cm (slightly ABOVE normal)

(Data courtesy Environment Canada)

Year in Review 2019

YQM 2019
Most major centres across Southern Canada were slightly colder than normal in 2019 with only the Arctic region posting above average values.

Greater Moncton was no exception at 0.1 degree below normal which was in contrast to 2018 which was 0.4 degrees above normal.

Based on the thirty year period from 1981-2010, Moncton had more hot days and fewer frigid days in 2019 but other categories were close to average.

Rainfall was above normal for Southeast New Brunswick while less snowfall was recorded for the year.

Mild but stormy conditions

A break in the rain at Irishtown Nature Park reservoir, 15 Dec 2019 (Dearing)

Another intense low pressure system moved through the Maritimes on the weekend bringing a new round of heavy rain and strong winds.

After a bone-chilling start, winds changed direction and a southerly flow pushed the high in Greater Moncton to 13.8°C – close to the record of 13.9°C from 2008.

Winds were strong with gusts up to 87 km/h in Southeast New Brunswick and a peak of 91 km/h reported in Bathurst.

As the storm headed to Newfoundland, cold air plunged into the region and temperatures fell below freezing and may stay that way for several days.

Heavy rain may cause flooding

Snow settles in Moncton, 05 Dec 2019 (Dearing)

The latest low pressure to invade the Maritimes is bringing heavy rain and strong winds to Southern New Brunswick and Northern Nova Scotia.

Environment Canada has issued a rainfall warning with up to 70 mm possible especially along the Fundy coast and strong winds gusting up to 90 km/h.

Meteorologists say that much rain is a lot for frozen ground to absorb and along with an existing snowpack could create localized flooding.

After a few days with below freezing temperatures, the small amount of snow in Greater Moncton has been taken away by the rain and a mild high of 12°C.

The forecast is calling for much colder air behind this system with some snow likely on Wednesday.

November 2019 – Colder and snowier

Ice forms on Irishtown Reservoir after cold night, 13 Nov 2019 (Dearing)

November got off to a mild start in Greater Moncton – the monthly high 19.4 C was actually 0.1 degrees warmer than October’s maximum – but temperatures quickly tumbled especially overnight.

Only two nights were actually above freezing with the coldest weather around the middle of the month.

The first measurable snow was recorded on 07-8 (18.8 cm) which was more than half of the November total and rainfall was lighter than usual.

Daytime highs struggled to climb above freezing especially during the last two weeks which led to a below normal monthly average.

NOVEMBER 2019 ALMANAC (at Greater Moncton Int’l Airport, 1981-2010)

Average HIGH 4.6°C

Average LOW -3.7°C

AVERAGE 0.5°C (about 1.4 degrees BELOW normal)

Extreme HIGH 19.4°C (01 Nov)

Extreme LOW -10.9°C (17 Nov)

RAINFALL 66.7 mm (about 20 percent BELOW normal)

SNOWFALL 32.5 cm (almost double, well ABOVE normal)

(Data courtesy Environment Canada)

First Below 0°C Daytime High

First Below 0
Cold, wintry weather seems to have arrived earlier this season in New Brunswick and Greater Moncton is no exception.

As shown above, the first below freezing daytime high was recorded on 09 November which makes it the earliest date in recent years.

In addition, the thermometer has already dropped to -10°C this month which I will outline in an upcoming post.

(Data courtesy Environment Canada)

Sharp drop in temperature!

Temperature contrast 8pm, 12 Nov 2019 (earth nullschool.net)

Snow began falling in Southeast New Brunswick Monday night and later changed to freezing rain and then rain by Tuesday afternoon.

The temperature climbed to a balmy 14°C in Greater Moncton and 18°C in Greenwood, Nova Scotia.

But as the low pressure system moved out of the Maritimes toward Newfoundland, winds shifted to the northwest causing the thermometer to drop rapidly Tuesday night with a return to snow when it fell to freezing again.

Overnight low records could be challenged in the region by early Thursday as cold Arctic air takes hold.

October 2019 – Gradual easing into fall

Centennial Park, Moncton, 14 Oct 2019 (Dearing)

Daytime highs were consistently in the mid-teens in Southeast New Brunswick during October which usually sees a sharp drop in temperature as the month progresses.

The average temperature was 0.7°C above normal in Greater Moncton with two days failing to reach 10°C and the warmest maximum on the last day, 19.3°C.

Six days had lows below freezing with some light frost but there was no hard freeze allowing vegetation to flourish.

The precipitation total mostly came from five rainfall events with not a single snowflake recorded.

Fall foliage peaked prior to Thanksgiving weekend and several strong wind events left few leaves on trees by Halloween night.

OCTOBER 2019 ALMANAC (at Greater Moncton Int’l Airport, 1981-2010)

Average HIGH 13.5°C

Average LOW 3.0°C

AVERAGE 8.3°C (about 0.7 degrees ABOVE normal)

Extreme HIGH 19.3°C (31 Oct)

Extreme LOW -2.7°C (27 Oct)

RAINFALL 102.7 mm (slightly BELOW normal)

(Data courtesy Environment Canada)

Growing seasons in Greater Moncton

Growing Season

Data courtesy Environment Canada

After taking a look at the past seven growing seasons in Greater Moncton including 2019, the last freezing temperature in Greater Moncton in the spring has been recorded from a month-long period from early May to early June.

Meantime in the fall, the first freezing temperature has been recorded from a month-long period from mid-September to mid-October.

The total number of days above freezing during the growing season has ranged from as little as 111 days to as many as 155 days – a difference of more than one month.