Wind Reading and Altitude Legality Interpreter

Whether a wind reading leaves a performance eligible for a record, under World Athletics Competition Rule 31 — and what the rule does not do. It does not correct the time, there is no altitude limit at all, and a raw +2.03 is recorded as +2.1, which makes it illegal.

What the rule covers, and what it leaves alone

The rounding rule, which decides more cases than the limit does

What the wind and the altitude are actually worth — unofficially

A threshold, a rounding rule, and nothing about altitude

This page is about athletics — track and field, and road running — whose competition rules, technical rules and scoring tables are published by World Athletics, the body that was the IAAF until 2019. Where a figure below belongs to a particular edition of those rules, the edition is named beside it, because World Athletics revises them and a number quoted without its edition will be wrong for somebody.

The rule decides eligibility and does not correct the performance. World Athletics Competition Rule 31, in the edition effective 1 November 2021, says of a record in a running event up to and including 200m that “if the wind velocity, measured in the direction of running, averages more than 2 metres per second, the performance will not be ratified”, and repeats the sentence for the long jump and the triple jump in the direction of jumping. Nothing in that rule adjusts a time or a distance. The result stands in the competition, it places the athlete, and it simply cannot be ratified as a record.

The limit itself is simple and its wording matters. Competition Rule 31 refuses ratification where the wind “averages more than 2 metres per second”, so a recorded +2.0 is legal and a recorded +2.1 is not. It covers outdoor running events up to and including 200 m, the long jump and the triple jump, and the average across a combined event. It covers nothing else: there is no wind limit on a 400 m, a 5,000 m, a high jump or a discus, and no wind gauge is required for them.

The rounding decides more marginal cases than the limit does, and it is the thing almost nobody knows. The Technical Rules require a reading to be “rounded to the next higher tenth of a metre per second, unless the second decimal is zero”, in the positive direction, and give their own examples: +2.03 is recorded as +2.1, and −2.03 is recorded as −2.0. So a raw gauge reading of +2.01 produces a recorded +2.1 and an unratifiable performance, while a raw +2.00 is legal. The field on this page asks for the recorded tenth for that reason, and refuses to rule on a two-decimal figure rather than rounding it the ordinary way, which would call a +2.03 legal. The gauge itself sits “beside the straight, adjacent to lane 1, 50m from the finish line” and is read for 10 seconds from the starter’s gun in the 100 m, 13 in the hurdles, and 10 seconds from the moment the first athlete enters the straight in the 200 m.

Altitude is a different matter, and the honest answer is that there is no rule. World Athletics sets no altitude limit for a record; a performance above 1000 m is ratifiable, and the “A” that statisticians and some national bodies attach to such a mark is a convention rather than a regulation. The assistance is real — thin air reduces drag, which is why the sprints and the horizontal jumps are the events where altitude shows in the record books — and it is simply unregulated. The altitude field on this page therefore changes the note and never the verdict, which is the only honest thing it can do.

Does anything correct for either? Not officially. The only published model found for this page is J. R. Mureika’s 2001 preprint on the legality of wind and altitude assisted sprint performances, which gives a closed-form correction to a still-air sea-level equivalent and a table of its values; on that model a legal +2.0 tailwind is worth about 0.10 s over 100 m for men and 0.12 s for women, and 2000 m of altitude adds roughly another 0.05 s. The paper offers it as something that “may be used track-side by coaches, officials and the media” to gauge a performance, not as a procedure, and World Athletics neither publishes nor applies any correction. The figures are printed above to show the size of what the rule declines to adjust, and they should not be quoted as official, because they are not.

One source disagreement is worth recording rather than reconciling. For combined events, the Competition Rules PDF read for this page carries only the plus-2.0 average. World Athletics’ own records-rules web page still prints a second, alternative condition — “the wind velocity in any individual event shall not exceed plus 4 metres per second” — and says at least one of the two must be met. One secondary account says the four-metre alternative was removed in 2010. Both readings are on this page because the governing body’s own two publications do not agree, and the rule book is the one this interpreter implements.

For the track the reading was taken on, the track lane distance and stagger calculator has the geometry and the rule numbers that go with it. For what a time is worth once it is accepted, the combined events scoring calculator does the decathlon and heptathlon points, and the combined-events wind average above is the one place the two subjects meet.

Frequently asked questions

Related calculators

References

1. World Athletics. Competition Rules (Book C, C1.1), Part III, Rule 31 — Specific Conditions. For a record in a running event “outdoors up to and including 200m”: “if the wind velocity, measured in the direction of running, averages more than 2 metres per second, the performance will not be ratified”, with the same sentence for the Long Jump and Triple Jump “in the direction of jumping”; and for combined events, “the average velocity (based on the algebraic sum of the wind velocities, as measured for each individual event, divided by the number of such events) shall not exceed plus 2 metres per second”. Copy read 12 Oct 2026, amendments approved 28 July 2021 and effective 1 November 2021; about 100,000 characters received and truncated inside the World Indoor Records section, so nothing later is relied on. This edition contains NO individual-event limit of 4 metres per second for combined events.
2. World Athletics. Technical Rules (Book C, C2.1), copy read 12 Oct 2026 carrying amendments effective 1 January 2022; about 60,000 characters of readable text, truncated before the combined-events material. The wind gauge stands “beside the straight, adjacent to lane 1, 50m from the finish line” and is read from “the flash / smoke of the Starter’s gun” for 10 seconds in the 100m, 13 in the hurdles and 10 from the first athlete entering the straight in the 200m. A reading is recorded “rounded to the next higher tenth of a metre per second, unless the second decimal is zero” in the positive direction, so “+2.03 … shall be recorded as +2.1” and “−2.03 … as −2.0”. A time is recorded “to the next longer 0.01 second” for races up to and including 10,000m and a hand time “to the next longer 0.1 second” — in both cases away from the athlete.
3. World Athletics. “Records rules”, worldathletics.org/records/recordsrules (read 12 Oct 2026). Cited because it DISAGREES with the rule book above: it still prints “the wind velocity in any individual event shall not exceed plus 4 metres per second” alongside the plus-2.0 average, with “at least one of these conditions” to be met, where the rule book carries only the average. Both readings are on the page rather than one being chosen quietly. About 4,000 characters, and it states no wind limit for individual events at all.
4. Mureika, J. R. “The Legality of Wind and Altitude Assisted Performances in the Sprints.” arXiv:physics/0102039 (2001), Department of Physics, University of Toronto. Equation 2, a “back-of-the-envelope” correction to a still-air sea-level equivalent: t₀,₀ ≃ t_w,H[1.03 − 0.03 exp(−0.000125H)(1 − w t_w,H/100)²]. Table 1 gives 100m corrections against a 10.00 s sea-level still-air baseline, from −0.04 s for still air at 1000 m to −0.17 s for +2.0 m/s at 2000 m. States that performances above 1000 m are “altitude-assisted” and that “these can and have qualified for record status”. Read 12 Oct 2026 from the ar5iv rendering; about 8,000 characters of prose with Table 1 readable as text, truncated inside the 200m discussion, so only the 100m figures are used. NOT official: the paper offers the correction as something that “may be used track-side by coaches, officials and the media … to gauge its overall ‘quality’”, and World Athletics neither publishes nor applies any wind correction.
5. Wikipedia. Wind assistance (read 12 Oct 2026; about 9,000 characters). “If a tail wind exceeds 2 metres per second … the result can not be registered as a record on any level”; “the wind assistance maximums are only in regard to the validation of a record” and “the results within that competition are still valid”. For combined events it adds that “higher average velocity was previously allowed as long as no individual event would exceed +4.0 m/s, but World Athletics removed this rule in 2010”. Cited for that 2010 removal, which is the only account found of why World Athletics’ own records page and its own rule book disagree; not a governing body.