Extreme heat lowers competition scores

The summary today

A single study, but a large and well-built one: 35,954 performances by 3,196 Chinese professional archers in the qualifying rounds of 460 events between 2010 and 2016, matched to the weather of the day, with each archer compared against himself. Above a heat index of 34 degrees the mean score per arrow falls by between ten and thirteen per cent. The most useful figure for an archer, though, is not the threshold but the shape of the curve: a few points are already lost between 22 and 26 degrees, about three per cent, and the loss grows from there. What counts is the combination of temperature and humidity, because relative humidity on its own has no measurable effect; some wind softens the loss in moderate heat but not in extreme heat; a seventy-two arrow event suffers no more than a thirty-six arrow one. Extreme heat penalises the weaker archers more and widens the gap to the best, while there is no difference between men and women. A single study, however large, is not enough for corroborated: that is why the status is "Reported".

Also phrased as: "you shoot worse in the heat"; "heat costs points"; "how much the temperature matters in competition"; "shooting in the sun and the score"; "humidity and competition scores"

Evidence

• 2021
  For Archers Published later

  Chinese professional archers in outdoor qualifying rounds between 2010 and 2016, with the weather of the day matched to the event and a fixed effect for each archer: compared with the 18 to 22 degree heat index band, above 34 degrees the mean score per arrow loses 1.07 points (minus 13.5 per cent) with no wind and 0.82 points (minus 10.4 per cent) at the sample's mean wind of 2.35 metres per second. The sample mean is 7.91 points per arrow. The figures come from the working paper deposited on SSRN: the published version is not open access and may differ.

  Adaptation and the distributional effects of heat: Evidence from professional archery competitions · Yun Qiu, Jinhua Zhao

• 2021
  For Archers Published later

  The fall does not begin at extreme heat. With no wind the score per arrow loses 0.25 points (minus 3.2 per cent) between 22 and 26 degrees of heat index, 0.42 points (minus 5.3) between 26 and 30 and 0.41 points (minus 5.2) between 30 and 34; at mean wind the losses in that band drop to 0.19 to 0.29 points. This is the inverted U-shaped curve, and it says that a few points go even on a day nobody would call extreme.

  Adaptation and the distributional effects of heat: Evidence from professional archery competitions · Yun Qiu, Jinhua Zhao

• 2021
  For Archers Published later

  The comparison between scenarios is the part that matters to anyone planning a season: for the same rise in mean heat index, about two degrees, doubling the frequency of days above 34 degrees lowers mean scores by about twenty per cent more than a uniform two-degree warming, and the probability of arrows in the ten by about a hundred and thirty-three per cent more. It is not only how hot it gets, it is how many extreme days turn up.

  Adaptation and the distributional effects of heat: Evidence from professional archery competitions · Yun Qiu, Jinhua Zhao

• 2021
  Context Archers Published later

  Who loses more: with a heat index above 34 degrees the gap between the highest and the lowest mean score in the event grows by 79.1 per cent and the coefficient of variation by 105.2, while the top ten per cent are hit significantly less. Extreme heat widens the gap rather than levelling it.

  Adaptation and the distributional effects of heat: Evidence from professional archery competitions · Yun Qiu, Jinhua Zhao

• 2021
  Context Archers Published later

  There is no difference between men and women: the interactions between sex and heat bands are not significant, either for the mean score or for the percentage of tens, with a single marginal exception between 26 and 30 degrees. The sample is 53 per cent men and 47 per cent women.

  Adaptation and the distributional effects of heat: Evidence from professional archery competitions · Yun Qiu, Jinhua Zhao

• 2021
  Context Archers Published later

  Wind should be read together with the heat, not instead of it. With no wind the losses between 22 and 34 degrees run from 0.25 to 0.42 points per arrow; at the sample's mean wind of 2.35 metres per second they drop to 0.19 to 0.29. Above 34 degrees, though, wind does not save anything: the loss stays at 0.82 points, 10.4 per cent. The interaction between wind and heat index is 0.00655 (p < 0.05).

  Adaptation and the distributional effects of heat: Evidence from professional archery competitions · Yun Qiu, Jinhua Zhao

• 2021
  Context Archers Published later

  What kind of heat is meant: the combination of temperature and humidity, that is the heat index, rather than humidity on its own. In the specifications that separate them, relative humidity is never significant and the coefficients for temperature alone are smaller than those for the heat index. Mean humidity in the sample is 75.1 per cent, ranging from 30.4 to 98.3.

  Adaptation and the distributional effects of heat: Evidence from professional archery competitions · Yun Qiu, Jinhua Zhao

• 2021
  Context Archers Published later

  The length of the event does not change the picture: the interactions between a seventy-two arrow event and the heat bands are not significant (0.0819 between 30 and 34 degrees, minus 0.252 between 26 and 30). It should be said that among thirty-six arrow events 72 per cent are held in one day, while among seventy-two arrow events 65 per cent are spread over two or more days, so the comparison is not between two identical days.

  Adaptation and the distributional effects of heat: Evidence from professional archery competitions · Yun Qiu, Jinhua Zhao

Status history

1. 1990 Not studied No study in the registry's bibliography had yet related the weather on the day of a competition to archers' scores. Heat was something archers talked about, not something in the data.
2. 2021 Reported A single study arrives, but a large and well-built one: 35,954 performances by 3,196 Chinese professional archers in the qualifying rounds of 460 events between 2010 and 2016, with fixed effects comparing each archer against himself. Above a heat index of 34 degrees the score per arrow falls by between ten and thirteen per cent, and the fall starts earlier, with minus 3.2 per cent already between 22 and 26 degrees, along an inverted U-shaped curve. The design is strong for observational data, but one study and one federation are not enough for corroborated: reported.

Related

Related articles

• Wind and weather conditions in archery: how to read and manage themHow far the wind moves an arrow and why, how many points it costs, how to read and correct for it, and what the data say about rain, cold and heat.
• Shooting in the heat: how many points go, who loses most and what reduces the lossHow many points heat costs in competition, where the loss begins, who loses most and what reduced it across 3,196 professional archers.

Research lines

• 102 studiesFrom the total on the scorecard to the arrow's coordinates
• 21 studiesDistance, group size and score

Other claims in this domain

• CorroboratedAbout 150 points on a FITA round separate a club archer from a national-team archer13 studies · 492 archers measuredStatus since 2003
• CorroboratedAn archer's arousal rises with what is at stake, and keeps rising as the competition goes on3 studies · 23 archers measuredStatus since 2011
• CorroboratedArchers are more aroused in competition than in training5 studies · 50 archers measuredStatus since 2025
• CorroboratedAt 70 metres a top archer averages about nine points per arrow7 studies · 72 archers measuredStatus since 2012
• CorroboratedEven in competition at the highest level, most arrows are not tens4 studies · 3,212 archers measuredStatus since 2024

See all claims on competition and scoring