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What the new data shows is that in many cities and towns, average monthly temperatures have increased, in some cases by more than three degrees Celsius.

In Toronto, the most recent normals show that average temperatures are half a degree to one degree higher most months compared to what was considered normal for the period between 1961 to 1990.

In northern cities such as Whitehorse, the changes are more pronounced.

The latest average (鈥渘ormal鈥�) for the city in January is -15 C, 3.7 degrees Celsius warmer than it was in the normals released 30 years ago. In December, it鈥檚 3.1 degrees Celsius higher.

Experts say those degrees matter.

鈥淓very degree of temperature change can have exponential impacts on climate conditions,鈥� said Dan Henstra, a political science professor and co-lead of the at the University of Waterloo.

鈥淲armer air carries more moisture, meaning more potential for more extreme rainfall and even extreme snowfall,鈥� said Henstra. 鈥淎verage temperatures, even one degree warmer, can exacerbate heat waves in the summer months, which are already unbearable for many residents in cities like 海角社区官网and other dense urban areas who don鈥檛 have access to air conditioning.鈥�

Residents in cities can be especially vulnerable because concrete and other materials absorb the warmth and re-emit it, leading to heat islands 鈥� areas that are hotter than those with more natural vegetation.

In northern areas of the country, the warmer temperatures can lead to permafrost thaw, which can cause roads to heave in the freeze and thaw cycle.

The new normals vs. El Ni帽o

The new normals have been released at the same time that Environment Canada modelling is predicting the entire country can expect a fall and winter that is warmer than even the new 30-year normals.

Part of that warmth could come from El Ni帽o, a warmer weather pattern in the Pacific, which the National Oceanic and Atmospheric Administration confirmed began in June and could be moderate to strong by late fall or early winter.

The World Meteorological Organization (WMO) predicts a high probability that one of the next five years will be the hottest on record due to El Ni帽o, which could result in a rise in the annual mean global temperature of between 1.1 to 1.8 degrees in the next five years.

The weather pattern is expected to lead to an increase in temperatures over Alaska, Yukon, B.C. and, to some extent, the Prairies, as well as an increase in precipitation on the U.S. West Coast.

It鈥檚 less certain if it will bring more precipitation to Canada鈥檚 West Coast, because El Ni帽o doesn鈥檛 typically have the same impact as it does further south, said Greg Flato, director of the Climate Research Division of Environment and Climate Change Canada (ECCC).

Modelling by ECCC didn鈥檛 show a high probability that the next six months would be wetter, or dryer, than normals for most of the country.

Currently, the global average temperature is 1.1 degrees above the pre-industrial average. The global average is used because warming won鈥檛 occur everywhere at the same rate.

Under the Paris Agreement, countries have pledged to try to keep the global long-term average temperature from increasing much more than one and a half degrees, and ideally well below two degrees relative to pre-industrial temperatures, said Flato.

The new normals from ECCC show that some Canadian cities have warmed close to a degree or more compared to normals 30 years ago.

鈥淔rom that point of view, one degree is big because that鈥檚 kind of the same target that we鈥檙e trying to not let the global average temperature get too much above,鈥� said Flato.

A historical bookmark

The normals released by ECCC are calculated once a decade using data from the preceding 30 years, a time period defined by the WMO as a kind of standard that averages out 鈥渢he day-to-day, year-to-year variability that is the weather we experience,鈥� said Flato.

It 鈥済ives you an indication of the average conditions over that 30-year time frame,鈥� said Flato. 鈥淎nd we refer to those as climate normals.鈥�

Unlike weather predictions, which provide an actual value for temperature or precipitation, the normals are used for comparison to indicate whether temperature or precipitation will be above or below normal.

There is data going back to 1850, but more recent data is used for the normals because 鈥渘obody alive today has any recollection of what the 1850 to 1900 average was like,鈥� said Flato. 鈥淪o it鈥檚 not so compelling.鈥�

However, when it comes to climate change, it鈥檚 the historical data that is used as the marker to measure the increase in the average global temperature because it predates the emission of greenhouse gases from human and industrial activities, according to the WMO.

And Canada has been warming more quickly than the global average because the country鈥檚 land mass is large and warms more quickly than ocean areas.

And in the higher latitudes of the country, particularly in the Arctic, warming is happening more quickly because of the loss of snow and sea ice, creating larger areas of open ocean, a darker surface that absorbs more solar radiation.

鈥淚n Canada, (the increase) is more like two degrees,鈥� said Flato. 鈥淎nd if you go to Canada鈥檚 North, it鈥檚 closer to three degrees.鈥�

The first release of the normals data didn鈥檛 include a large number of Canada鈥檚 major cities or towns. Nor does it break precipitation down into how much snowfall, versus rain, a city had per month. More detailed information, as well as data for more municipalities, will be released in stages.

But Flato said data already shows the snow cover season is getting shorter over most places in Canada, aside from a few areas in the mountainous parts of the Rockies.

鈥淭he snow doesn鈥檛 stay on the ground until later in the fall and it melts away earlier in the spring,鈥� said Flato. 鈥淪o the snow cover season is getting shorter almost everywhere. And that鈥檚 a direct consequence of it being warmer.鈥�