Sideline Sky Check a field

Game-day weather for outdoor youth and rec sport

Know the heat.
Watch the sky.
Call it early.

Type the field's ZIP code. Sideline Sky reads the National Weather Service forecast for that spot and lays out every hour of the next week: heat stress (WBGT) against the activity table you use, thunder chance, rain, wind and any active alert. When thunder rolls, the shared 30-minute lightning clock keeps everyone on the same count.

Sample day · made-up numbers, real level math

Peak forecast WBGT

85.2°F

at 3 PM · Level 3 on the Category 2 table

  1. 7a71.2 °F, Level 1, thunder 0%
  2. 8a73.0 °F, Level 1, thunder 0%
  3. 9a75.4 °F, Level 1, thunder 0%
  4. 10a77.9 °F, Level 1, thunder 5%
  5. 11a80.1 °F, Level 2, thunder 5%
  6. 12p82.3 °F, Level 2, thunder 10%
  7. 1p83.8 °F, Level 2, thunder 15%
  8. 2p84.6 °F, Level 2, thunder 25%
  9. 3p85.2 °F, Level 3, thunder 35%
  10. 4p84.0 °F, Level 2, thunder 40%
  11. 5p81.7 °F, Level 2, thunder 30%
  12. 6p79.0 °F, Level 1, thunder 20%
  13. 7p76.3 °F, Level 1, thunder 10%
  14. 8p74.1 °F, Level 1, thunder 5%
Best 90-minute window, thunder at most 20%: 8 AM to 10 AM, peak 75.4 °F.

Three calls, one page

Heat

Forecast wet bulb globe temperature for every hour, coloured Level 1 to Level 5 against the table you pick: one of the three regional tables from the Korey Stringer Institute, or your own association's numbers. Heat index alongside, with the Weather Service's bands.

Run a field check

Sky

Chance of thunder and rain by the hour, wind and gusts, and every active National Weather Service alert for that point, on top of the page. The window finder picks the coolest start each day that keeps thunder under your limit.

How the numbers work

Clock

"Wait at least 30 minutes after the last thunder before resuming outdoor activities," says the Weather Service. Start a clock, send its link to the other coaches and the officials; anyone can press "Thunder heard" and it starts again from 30:00 for everyone.

Start a lightning clock

Pick the table your league uses

WBGT in °F where each level starts. Level 1 is activity as normal; Level 5 is the table's cancel or stop band. What changes in between (rest breaks, equipment, practice length) is your association's policy, so Sideline Sky shows the level and leaves the rule to you.

Category 1

cooler regions; the most cautious of the three

  1. Level 586.1 and over
  2. Level 484.1 to 86.0
  3. Level 381.1 to 84.0
  4. Level 276.2 to 81.0
  5. Level 1under 76.2

Category 2

middle regions

  1. Level 589.7 and over
  2. Level 487.7 to 89.6
  3. Level 384.7 to 87.6
  4. Level 279.8 to 84.6
  5. Level 1under 79.8

Category 3

hottest regions

  1. Level 592.0 and over
  2. Level 490.1 to 91.9
  3. Level 387.0 to 90.0
  4. Level 282.0 to 86.9
  5. Level 1under 82.0

Source: Korey Stringer Institute regional WBGT categories, from Grundstein et al., "Regional heat safety thresholds for athletes in the contiguous United States," Applied Geography (2015). Find your region on KSI's map or use your state association's own numbers.

Safety is free. The paperwork is Plus.

Field checks, alerts, the tables and lightning clocks are free for everyone, always. Plus keeps more venues and sessions on a Team Desk and a longer conditions log.

Free

$0

  • Field checks for any US location, unlimited
  • NWS alerts, heat index, thunder and rain chance
  • All three regional tables, or your own numbers
  • Lightning clocks, unlimited, shareable
  • Team Desk: 1 venue, 3 weekly sessions, 14 days of conditions log

Sideline Sky Plus

$1.95 a month or $19.50 a year

  • Everything in Free
  • Team Desk: 12 venues, 40 weekly sessions
  • 400 days of conditions log, printable
  • CSV of the log for your season paperwork

Weekend Pass

$1.00 once

  • Plus limits on one Team Desk for 3 days
  • Made for a tournament weekend at several venues
  • No renewal, nothing to cancel

Free during preview. Nothing is charged. Payments are not switched on yet, so every Team Desk has the Plus limits for now. When checkout opens (PayPal), these prices apply, and the site will say so before anything is charged.

What Sideline Sky is not

  • Not a WBGT meter. A forecast is not a reading. If your policy says to measure on site, measure on site.
  • Not a lightning detector. If you hear thunder or see lightning, stop and start the clock, whatever the forecast said.
  • Not medical advice and not an official National Weather Service product.
  • Never says "safe". It shows the numbers and your table; the adult in charge makes the call.