Winter is Coming – Are You Ready for Inclement Weather?

Last Updated on: 10th January 2023, 01:52 pm

OSTA’s decision on whether to cancel services or not weighs the degree of risk based on each weather event and its effect on our environment and the potential for accidents. Student safety is always our priority.

OSTA’s transportation system serves urban, suburban and rural communities. We also recognize weather conditions can vary from community to community.

Cancelled Services

OSTA’s decision to cancel services must consider the forecasted weather for the entire school day. Whether the risk is too high during the morning service or anticipated to be too high during the afternoon service, a decision is made by 5:30 a.m.

OC Transpo, however, continues to operate, and students may use public transit to get to their school. Schools remain open, and students will be welcomed, as usual. Ottawa Safety Council determines service cancellations for OSTA’s Walking School Bus routes.

Parents’/Guardians’ Decision

Parents and guardians have the choice of whether to access OSTA’s transportation services during a weather event or whether to keep their children at home. Conversely, parents and guardians may also choose to take their children to school when transportation services are cancelled. If they do so, they must also make arrangements to pick their children up at the end of the school day.

Communication Channels

There are many ways parents/guardians and students may get information regarding OSTA’s service cancellations:


Daily – OSTA reviews forecast reports from various accredited sources. If a weather event is expected, which may significantly impact safety, OSTA proceeds to further steps.

4:00 a.m. – 5:30 a.m. – OSTA reviews the forecast and examines current weather patterns from various sources, including weather radars. OSTA communicates with neighbouring consortia and other transportation partners to get their input on conditions in their area. OSTA may also conduct a road test.

5:30 a.m. – OSTA decides whether or not to cancel transportation. If the decision is made to cancel services, OSTA begins its communication protocol.

6:15 a.m. – OSTA communication protocol is complete.

Weather Conditions to Consider

There are many conditions, in combination, that increase risk. There is no absolute determinant for service cancellations. Conditions are evaluated as a whole to determine risk:

  • Type of Precipitation (Snow/Rain/Snow-Rain Mix)
  • Amount and Rate of Precipitation
  • Air/Road temperature and dew point
  • Wind speeds/wind gusts affect bus/van stability on icy surfaces, visibility related to the rate of precipitation and or blowing in open spaces
  • The condition of roads at the time of weather events such as bare pavement, patchy ice, glare ice, icy ruts, packed snow, loose accumulation, slushy, slick and combinations.
  • The visibility such as the line of sight to distance, visibility of roadway, blowing snow coming down or across sightline, snow drifts, etc.
  • The probability of precipitation may be low, mid-range or high, combined with expected accumulation (low, medium, high volumes) determines the likelihood of anticipated weather effect actually occurring at the estimated times
  • Radar models show consistent path across the region or potential re-direction

No Temperature Thresholds

Throughout the winter, temperatures may dip as low as -25C to -35C plus wind chill. Ottawa Public Health provides a “frostbite warning” or a “frostbite advisory”. Parents must always take the appropriate precautions to dress their children warmly, preferably in layered clothing, coat and snow pants with hat and mittens or gloves and a face cover where necessary. They must also stay with their children at the bus stop.

OSTA does not have a temperature threshold at which it will cancel services, except if the equipment is adversely affected and buses cannot start in the extreme cold. That would generally require an ambient temperature (no wind chill) of -40C or lower, which is highly unusual in the Ottawa Region.

Read more about inclement weather.