Weather Conditions and Reports

From month to month, Manitoba's ag weather program retrieves data every 15 minutes from equipment across the province. About 109 stations monitor air temperature, relative humidity, rainfall, wind speed/wind direction and soil temperature.

In addition to regular weather and soil reports, producers can access more specialized tools during the growing season. These tools include disease and crop condition reports, which helps producers determine the safest and most effective times to spray.


Latest weather and conditions

1.    Seven-Day Accumulated Precipitation (Sept 10 - 16, 2018) shows the amount of precipitation received across agro-Manitoba last week. Areas around the southern Interlake (Inwood and Lake Francis) and northern parts of the Eastern region (Beausejour, lac Du Bonnet) received between 50 – 75 mm of rain last week. The highest amount of precipitation was at Wawanesa with a total of 75 mm which is due to the 53 mm of rain the area received on Wednesday, Sept 12 between 10:30 pm and midnight. All regions got some rain last week although areas west of Eden to the Saskatchewan border received only 2 – 10 mm.  

2.    Total Accumulated Precipitation (May 01 – Sept 16, 2018) showed improved precipitation especially around Wawanesa, Winnipeg, southern Interlake and northern parts of the Eastern region based on last week’s rainfall events. Few areas with less than 200 mm of precipitation since May 1 are Rorketon, Laurier, Reedy Creek, Lake Audy (Northwest region); Birtle, Brandon, Ninette (Southwest region) and Treherne, Elm Creek, Kane and Altona (Central region). 

3.    Percent of Normal Accumulated precipitation (May 01 to Sept 16, 2018) relates accumulated precipitation since May 1 to a 30-year historical record. Areas in the Northwest and Southwest regions close to the Saskatchewan border have above normal precipitation mainly due to a single rainfall event which occurred in early June. Most of agro-Manitoba are between 65 – 95% of normal precipitation since May 01. Areas with less than 200 mm listed above are mostly between 55 and 65% of normal precipitation. 

4.    Soil Moisture (Sept 16, 2018, top 0-30 cm) shows that agro-Manitoba is mostly dry to adequate soil moisture condition. The southwest, Interlake and southeast corner of the province showed dry soil moisture condition. The central and northwest regions are mostly at adequate soil moisture. The map shows soil moisture in the top 0-30 cm when compared to the soil saturation level (maximum recorded at that station). 

5.    Total Accumulated Growing Degree Days (base 5°C) from May 01 to Sept 16, 2018 shows that the south central part of the province has accumulated the highest growing degree days (max 1970 GDD). The northwest region has the lowest accumulated GDD at 1,347 – 1,450. Growing degree days are calculated by averaging daily maximum-minimum temperatures and subtracting 5°C which assumes that growth does not occur below this temperature. Heat accumulation generally decreases from south to north.

6.    Percent of Normal Accumulated Growing Degree Days from May 01 to Sept 16, 2018 shows the range in growing degree days for agro-Manitoba.  The climate normal is based on historical record over a 30-year period. Almost all the locations are warmer than normal accumulated GDD except Windygates, Snowflake, Oakburn and Pipelake which have accumulated below 100% of normal accumulated GDD. Wawanesa is the only station that has recorded over 20% above normal GDD accumulation.

7.    Total Accumulated Corn Heat Units from May 01 to Sept 16, 2018 shows that the southern areas of the central region of the province received the greatest accumulated corn heat units (maximum of 3030 units). Morden and Letellier have both accumulated over 3000 CHU. Heat accumulation generally decreases from south to north. Corn heats units are similar to growing degree days given they both assume that growth increases with increasing temperature but they are calculated differently.  Corn heat units calculates the day and night temperatures separately.  It is assumed that no growth occurs with night temperatures below 4.4°C or day temperatures below 10°C . Maximum growth occurs at 30°C and decreases with higher temperatures. 

8.    Percent of Normal Accumulated Corn Heat Units from May 01 to Sept 16, 2018 shows above normal CHU accumulation at most agro-MB regions (ranging between 97 – 117%). Areas around Elm Creek, Carberry and Minnedosa are between 16 – 17.4% warmer than normal based on the accumulated CHU this season relative to historical normal. The climate normal is based on historical record over a 30-year period.

9.    Total Accumulated Physiological Days (P-Days) from June 01 to Sept 16, 2018 shows greater heat accumulation in the central and southwest regions of agro-Manitoba. Similar to GDD and CHU, the P-day provides an indication of heat accumulation. However, it uses 7°C as the minimum air temperature for growth and development; rapid growth at 21°C and maximum growth at 30°C. P-Day is mostly used for Potato heat accumulation. A different start date (June 01) is used for P-days because accumulation commences at about 50% potato emergence. Other heat accumulation starts from seeding. Areas around Morden have the highest P-Day accumulation at 845 units. 

10.   Percent of Normal Accumulated P-Days from June 01 to Sept 16, 2018 shows that compared to historical accumulation, only areas around Minnedosa have received more than 10% of normal P-days heat accumulation. The heat indicators (GDD, CHU and P-Days) show that this growing season has been warmer than normal at almost all locations.

11.  The average daily soil temperature across agro-Manitoba can be found at (   

12.  The Manitoba Weather Report shows weather information by individual weather station. 

Please note that

·         In addition to providing air pressure and soil moisture and temperature data at 4 depths (5, 20, 50 and 100 cm), most stations now update every 15 minutes. Visit the station-specific pages at  

·         The Current Weather Viewer which displays up to the hour conditions at each weather station can be found here.


Weekly Maps

(Higher resolution is available on request)

Crop Weather Report


Fall Frost Report


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Seasonal maps

Visit the Seasonal Reports page for information on progress in seeding and crop establishment, crop development, pest activity including weeds, insects and disease, harvest progress, crop yields and grades, fall field work progress, and status of winter cereal crop seeding and establishment. Information on haying progress and estimated yields, as well as pasture conditions is included.