It's going to be an unseasonably hot day in Sydney on Sunday, with temperatures to climb close to the March records. Northwesterly winds persisting throughout the weekend ahead of an approaching cold front, are helping helping to funnel warm air from the interior of NSW over the city. While these winds should not be able to limit any seabreeze on Saturday, as they increase on Sunday, they will likely prevent a seabreeze from forming. It is the presence of a seabreeze today that should help to limit heating and cool the city in the afternoon. Even with these effects, it is still likely that temperatures will reach tops of 31 degrees (6 above average) in the city and 37 degrees in Penrith (9 above average) After the heat lingers overnight, temperatures are expected to jump during the day due to strong northwesterly winds and the lack of a seabreeze. The mercury should peak at 37 degrees in the city, and up to 41 degrees out west, 11 and 13 degrees above average respectively. Heat this significant at this time of the year is also quite unusual, even more so as this will likely be the second warmest day so far this year, only surpassed by a 43 degree day in early January. Although unusual, these temperatures are not record breaking, with the March maximum, which occurred in 1983, only a couple degrees higher than tomorrows forecast at 39.8 degrees. Following this peak, temperatures look to drop back to 30 on Monday, before gradually declining into the low 20’s by the end of the week. After this, it is unlikely that such extreme temperatures will be experienced again until the end of the year.