What To Expect For Weather And Temperatures In The Canadian Rocky Mountains

Unpredictable Rocky Mountain Weather

Knowing when the best time to plan a trip or how to pack for a visit to the Canadian Rocky Mountains can be challenging because it’s almost impossible to predict future weather or temperatures. Averages can be given as a general guideline, but they can be very unreliable due to the large variations that often occur.

Many factors influence the weather such as the latitude of the mountain parks and the pacific winds from the west. The mountains can practically make their own weather which means it can be very location specific, differing from one valley to the next. The conditions can change from day to day and even hour to hour. It’s possible to experience the weather of all seasons, rain, hail, snow and sunshine within one day!

The temperatures can vary greatly from day to evening. It’s not uncommon in the summer months to drop to near freezing during the night, even if the daytime temperature was in the upper twenties. Snow is rarer in the months of July and August, but it can and has fallen on any given day of the year. Considerable amounts of snow fall through the winter and through the spring with snow storms occurring as late as May. Hiking trails in the mountain passes don’t clear of snow until near the end of June or into July. High elevation lakes like Lake Louise are frozen until early June. The first snowfall of the season can be as early as September, but generally the larger dumps of snow don’t occur until November and December.

The Seasons Work Differently In The Mountains

The length of the seasons in the mountains differ in length compared to many other parts of the country. Winter is a extremely long and it seems to take it’s time transitioning into Spring. Spring, Summer and Autumn are short and the transition between those seasons is very quick. Autumn seems to be over before you know it and instead of two distinct seasons the next period seems like Spring with a short amount of summer tacked onto the end of it. Summer quickly transitions into Autumn and then before you know it the first dusting of snow can be spotted in the mountain tops, sometimes by early September.

Monthly Weather And Temperature Averages

Keep in mind there can be large fluctuations from the average monthly temperature and weather trends. With so much uncertainty it’s impossible to know what the weather will be like until a few days beforehand and even then the weather forecasts are not always reliable. Most of the information below is based on the town site area of Banff, the same information will be somewhat relevant for Jasper and Canmore. Although spring tends to arrive a little bit earlier in those places. Lake Louise tends to be colder and receives much more snow. Snow will still be covering the ground when spring grasses are starting to green up in lower elevations of Banff, Canmore and Jasper.

January

• Tends to be the coldest month.
• Average daily high of -5C. and lows of -15C.
• There can be cold snaps with bitter temperatures down to -25C  or colder that can last for days or up to a week.

February

• May be slightly warmer with average daily highs of 0C. and low of -12C.
• It’s not usually until mid-March that daytime temperatures will get up above freezing.
• Can still have bitter cold snaps.

March

• The  first month that feels like the grip of the winter season might be lessening its hold.
• It’s still very much winter and cold with an average daily high around 4C. and low of -8C.
• Much less chance of the bitter cold snaps that occur during the beginning of winter.

April/May

• April can still be considered the tail end of winter, daily high temperatures can be around 9C. and low of -3C.
• May can have a daily high temperature up to 15C. and low of 2C.
• Both of these are considered transitional months, temperatures can drastically fluctuate.
• Spring comes to the valley bottoms of Banff and Jasper by mid-April, snow starts to melt away.
• In higher elevations like Lake Louise the month of May is considered early spring, snow hangs around on the ground much longer.
• Spring snowstorms are still a possibility for all areas of the mountains.
• Road conditions at this time can be anything from bare dry pavement to areas of compacted snow and/or ice.

June

• June is getting warmer, but is considered the wettest month in the mountains.
• The amount of rain can vary from year to year. Showers are generally isolated and short in duration, rarely does it rain all day in one specific area.
• Daytime highs can be as high as 15C. to 18C. but it’s not uncommon for periods of colder temperatures during June. Lows can be down to 5C.

July and August

• These months have the warmest daytime temperatures with averages in the 20C. or higher range.
• July is generally the warmest month of the year. Low’s can be down to 6C. or 7C. for both months.
• There can be significantly cooler temperatures at night and in the early morning, it’s possible for it to drop down to near freezing.

September 

• In early September temperatures can start to cool off. Daytime highs can still be very pleasant at around 15C. with lows down to 3C.
• Sometimes summer extends itself and we are blessed with higher temperatures, but the evenings and mornings will be crisp.
• Each week in September usually gets progressively colder. There can be a big difference between the beginning and the end of the month.
• Shorter daylight hours have the evenings and mornings getting much colder.

October 

• October can have warm sunny days up to 10C. or higher with lows down to -1C.
• It’s another month where each week the temperatures progressively drops. The beginning and end of the month can be very different.
• The first signs of snow can start in late September or early October. Each year is different, sometimes there is no snowfall until November.

November 

• The temperatures continue to fall, by early November the daytime high won’t get above freezing.
• The first larger snowfalls usually occur in November.
• It’s a month of transition, sometimes not quite full winter. There’s not enough snow yet for many of the winter activities.

December 

• By early December the lakes have started or become frozen.
• There’s enough snow for winter activities to start up.
• The cold winter temperatures have set in with the average daily high around -5C. and lows of -14C.
• Cold snaps can start bringing much lower temperatures for days at a time.

BANFF

Average	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sept	Oct	Nov	Dec
Daily High (°C)	-5.3	0.1	3.8	9	14.2	18.7	22.1	21.6	16.1	10.1	0.5	-5.3
Daily Low (°C)	-14.9	-11.3	-7.9	-2.8	1.5	5.4	7.4	6.8	2.7	-1.1	-8.2	-13.8
Daily High (°F)	23	32	40	49	57	66	71	70	60	50	32	23
Daily Low (°F)	5	13	18	27	34	41	45	44	38	31	18	7
Rainfall (mm)	2.4	1.7	1.6	10.5	42.4	58.4	51.1	51.2	37.7	15.4	6	2.8
Snowfall (cm)	38.2	30	27	26.3	17.1	1.7	0	0	7	18.9	33.6	43.9
Hrs of Sun/Day	8.1	10	12	14	15.5	16.5	16	14.5	12.7	10.7	9	7.8

Average Temperatures For Jasper

High °F	Low °F		High °C	Low °C
26	9	January	-3	-13
31	12	February	0	-11
42	20	March	6	-7
52	28	April	11	-2
61	37	May	16	3
67	44	June	20	7
71	47	July	22	8
71	45	August	22	7
62	38	September	17	3
50	30	October	10	-1
33	17	November	0	-8
24	8	December	-5	-13
49	28	Year	10	-2

Special Notes About Rocky Mountain Weather And Conditions

• The wind chill factor can make the temperature feel much colder than it is. -20C. could feel like -30C. On days where it’s applicable it will be reported along with the actual temperature forecast. Take note of the windchill when dressing for the outdoors.
• On the flip side a warm wind known as a Chinook can quickly, but temporarily bring on spring like temperatures in the winter months. It can last for several days. Banff, Canmore and Calgary feel the effect of the Chinooks, but it’s not experienced as much in Lake Louise.
• The air in the mountains is very dry. This lack of humidity makes the extreme temperatures more bearable than areas with high humidity. The higher the elevation the drier the air is.
• Elevation also has a large influence on the temperature and weather. For every 200 meter increase the temperature drops by 1C.
• The length of daylight hours in the mountain parks varies greatly throughout the year. There is as little as 7.5 hours in December and up to 16 hours near the end of June.
• From November through March vehicles need to be winterized. They should be equipped with snow tires and carry an emergency kit.
• Avalanches can be a hazard in the parks, don’t assume there can’t be a risk when hiking in close vicinity of a resort. Know the dangers and safety precautions before hiking or skiing and check the latest reports by calling 1-800-667-1105 or online at Rocky Mountain parks safety and avalanche information.

Useful Tools For Weather And Temperature Forecasts

The various webcams can be a great way to get a glimpse of how things look prior to your arrival.

• Banff National Park webcams
• Jasper National Park webcams
• Canmore webcams

Environment Canada Weather Forecasts

SkiBig3 Snow and Weather Conditions for Mount Norquay, Sunshine Village and Lake Louise ski resorts.

AMA Road Reports – road conditions throughout the province of Alberta.

Drive B.C. Road conditions and webcams throughout the province of British Columbia.