Weather can change a race in minutes. In Vietnam, a clear early morning can turn into a thunderstorm, a tropical downpour or a sudden rise in heat after sunrise. Pacers are not weather experts, and the decision to delay, shorten or stop a race always belongs to the organiser. But your group will look to you for calm guidance. This lesson explains how to respond.
The golden rule: the organiser decides#
Do not change the pace plan on your own because of the weather (see heat and humidity). If conditions require an adjustment, the pacer coordinator communicates it to all teams. Before race day:
- Join the pacer messenger group and keep notifications on during the race.
- Know how the organiser will announce changes: loudspeakers, marshals, text messages or the messenger group.
- Agree in your team who checks the phone, usually a support pacer, so the leader can focus on the group.
When an instruction comes, pass it on clearly to your group with a short voice call and the matching hand signal, as in Lesson 3.1.
Lightning#
Lightning is the most dangerous weather risk for an outdoor event. Open roads, bridges and riverbanks are especially exposed.
- Follow organiser instructions immediately. If the race is paused or stopped, guide your group to the shelter the marshals indicate.
- A widely used safety idea is the 30/30 rule: if the time between seeing lightning and hearing thunder is 30 seconds or less, the storm is close enough to be dangerous, and people should wait about 30 minutes after the last thunder before going back outside.
- Safer shelter is a solid building or a hard-topped vehicle. Avoid open ground, isolated trees, metal fences and water.
- Do not argue with marshals to keep running. No finish time is worth the risk.
Heavy downpour#
Tropical rain can be intense. It rarely stops a race, but it changes how you run.
| Problem | What to do |
|---|---|
| Slippery footing | Shorten your stride, avoid painted road markings, metal covers and smooth tiles. Call "Slippery!" and point down at hazards. |
| Poor visibility | Keep the group compact, make calls louder and earlier, keep your flag upright. |
| Chafing and blisters | Remind runners before the race to use anti-chafe products; wet clothes rub more. |
| Getting cold | After the rain, runners can cool down quickly, especially slower runners. Watch for shivering. |
It is fine to run a few seconds per km slower on a dangerous surface. Safety comes before a perfect split.
Extreme heat spikes#
Sometimes the temperature and humidity rise far beyond the forecast. This is when you switch from pacing for time to pacing for safety.
- Follow any revised pace or instructions from the pacer coordinator. Tools such as the Weather compensator help coordinators plan adjustments before the race; on race day, follow their decision.
- Tell your group honestly: "It's very hot today. Today's goal is to finish safely."
- Encourage runners to slow down if they feel unwell, to use sponges and to cool down at water stations, and to drink regularly without over-drinking.
- Watch closely for heat illness: confusion, stumbling, slurred speech (see Lesson 4.1). Any of these means stop and call medics.
- Look after yourself too. A pacer who collapses cannot help anyone.
Key takeaways#
- The organiser decides on delays, changes or stopping the race; never change the plan on your own.
- Lightning: follow instructions at once, seek proper shelter and remember the 30/30 rule.
- Heavy rain: shorter strides, louder and earlier calls, a compact group and watch for chafing and cold.
- In extreme heat, switch from pacing for time to pacing for safety and watch for heat illness.
- Keep a team member on the phone so organiser messages reach the group quickly.
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