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 (August 06-12, 2018) shows the amount of precipitation received across agro-Manitoba last week. Only a handful of locations (The Pas, Shoal Lake, Killarney and Pilot Mound) had > 2mm. The Pas had the highest precipitation last week at 5.2 mm. 

2.    Total Accumulated Precipitation (May 01 to August 12, 2018) remained similar to last week’s total. The areas with low total precipitation in the southwest are Brandon, Forrest, Alexander, Souris, Wawanesa, Boissevain and Ninette; in the central region: Treherne, Elm Creek, Elie, Lakeland, Kane, Altona, Gretna, and Emerson; Northwest/Interlake region: Rorketon, Reedy Creek, Mooshorn, Taylor’s Point, Fisher Branch, Arborg ad Gimli. The listed locations have accumulated less than 160 mm of precipitation since May 01.

3.    Percent of Normal Accumulated precipitation (May 01 to August 12, 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. Most of agro-Manitoba are between 65 – 80% of normal precipitation since May 01.

4.    Soil Moisture (August 12, 2018, top 0-30 cm) shows that the many areas have dry soil moisture in the top 0-30 cm when compared to the soil saturation level (maximum recorded at that station). This is based on trace or no precipitation throughout last week.

5.    Total Accumulated Growing Degree Days (base 5°C) from May 01 to August 12, 2018 shows that the south central part of the province has accumulated the highest growing degree days (max 1517 GDD). The northwest region has the lowest accumulated GDD at 1,096 – 1,200. 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 August 12, 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 ranging from 98-125% of normal accumulated GDD. Carberry, Minnedosa and Wawanesa areas are over 20% warmer than normal.

7.    Total Accumulated Corn Heat Units from May 01 to August 12, 2018 shows that the south central and south west portions of the province received the greatest accumulated corn heat units (maximum of 2322 units). 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 August 12, 2018 shows above normal CHU accumulation at all agro-MB regions (ranging between 100 – 123%). Similar to the GDD, areas around Carberry, Minnedosa and Wawanesa have accumulated the highest CHU units. The climate normal is based on historical record over a 30-year period.

9.    Total Accumulated Physiological Days (P-Days) from June 01 to August 12, 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 (Central region) and Mountainside (Southwest region) have the highest P-Day accumulation at over 585 units.

10.   Percent of Normal Accumulated P-Days from June 01 to August 12, 2018 shows that compared to historical accumulation. Some areas in the Southwest region have received the highest percentage of normal P-days heat accumulation up to 13% above normal P-day accumulation at Minnedosa. 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. Heat wave brought record-breaking air temperature across agro-Manitoba. Elm Creek and Waskada tied for the maximum air temperature at 40.0°C yesterday, August 12.


Please note that the Current Weather Viewer which displays the conditions at each weather station found here is only available via Google Chrome on a temporal basis. Further support on all browsers is being tested. Additional geospatial viewers are available at

Note:  Barometric Pressure Sensors will be added to all weather stations in 2018 and this will enable “forecast” data” and to possibly include this into modelling products.  You will also note that each weather station will have 4 soil moisture probes recording information (5, 20, 50 and 100 cm) in 2018.  This data will become available as weather stations are upgraded.


Weekly Maps

(Higher resolution is available on request)

Crop Weather 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.