There are few instances in professional tennis that can bring matches to a standstill or suspend them to a different day or even venue, and one of those occasions is when it rains.
Weather forecast is perhaps one of the most telling pre-tournament or pre-match factors that players, fans, and tournaments take into consideration before even a ball is struck. For tournament organizers, contingency plans are necessary when rain is expected on a day's schedule.
For players, the possibility of rain or chilly conditions means that they need to strategize on how to play, and some players go to the extent of wearing leggings or layered clothing to warm up their bodies and prevent muscles from becoming stiff.
At a professional level, when it rains, matches are halted by the chair umpire. However, occasionally a few points would be played at the umpire and players' discretion provided the severity of raindrops is unlikely to cause any harm to the players and that the rain is considered a passing shower which won't result in a wet court.
Light showers most of the time result in matches being temporarily on hold to allow for the covers to go on, and give the courts time to absorb the excess water and dry it out. There are a number of reasons why it is impractical to play tennis when it is raining.
And inarguably, one of those reasons is the risk associated with slipping when it rains, and this could result in potentially serious injuries to a player. So taking extra precautions is critical. Stopping play during rain is also fuelled by the prospect of keeping the courts in their perfect condition.
We know grass and clay courts attract hefty maintenance costs and therefore, playing on them during rain would be extremely detrimental both in the short and long term as these surfaces can easily be damaged when extra pressure is applied while the courts are soggy.
While it is possible to play in light rain, it is often recommended not to, as this would tarnish the spirit of fairness. Weather can for the most part play a factor in the outcome of a match. In case of rain, the ball tends to become heavier and this in turn slows its bounce. So this could result in an unfair advantage for one of the players.
The workaround for heavy rains has always been the installation of retractable roofs which can turn an outdoor setting into an indoor match and allow for play to continue. All four Grand Slam tournaments, the Australian Open, Roland Garros, Wimbledon, and US Open have a roof in at least one of their main courts.