Five A-Leagues games have been postponed or given delayed kick-offs to avoid extreme heat forecasts in Adelaide and Melbourne.

Adelaide United's ALW clash with Wellington at Coopers Stadium on Tuesday 27 December, which was due to kick off at 5.05pm, has been postponed.

The kick-off time for the men's match against Newcastle has been pushed back half-an-hour to 7.45pm local time (8.15pm AEDT).

Western United's ALW clash with Newcastle on Wednesday 28 December at City Vista Recreation Reserve has also fallen victim to the weather forecast.

The A-Leagues are yet to provide dates for the rescheduled fixtures.

Meanwhile, Melbourne City's ALW team had been due to play Perth at 2.20pm at AAMI Park on Tuesday 27 December, with the club's men's team to face Central Coast at 5pm.

The ALW game will now kick-off at 8.15pm, after the conclusion of the ALM fixture which has been pushed back to a 5.30pm start.

City coach Dario Vidosic had on Thursday urged the league to reschedule the fixtures in the interests of player safety.

Extreme temperatures proved an issue for some teams earlier in the season, with several ALW players - including Brisbane's Shea Connors, Wellington's Alyssa Whinham and Victory's Tiffany Eliadis - substituted with heat exhaustion.

The Australian Professional Leagues' heat policy calls for matches to be delayed or postponed if the ambient temperature approaches 40C and/or the wet bulb globe temperature (WBGT) exceeds 28C.

Drinks breaks are implemented if the ambient temperature is in excess of 31C and/or the WBGT is 26-27.9C.