An excessive heat warning will be in effect through 8 p.m. Thursday for areas of San Diego County east of Interstate 15 as unseasonably warm weather spreads across most of California, the National Weather Service said. The daytime high temperatures in areas like Ramona and Alpine will be in the 98-to-100-degree range on Tuesday and will inch higher on Wednesday and possibly Thursday. Escondido and El Cajon will be in the mid- to upper 90s all three days. San Diego also will be unseasonably warm with daytime highs in the low 80s. Forecasters say the temperature will drop to the low 70s by 5:30 p.m. on Tuesday and Wednesday, roughly the time that the Padres will host the Atlanta Braves at Petco Park in National League playoff games. The heat wave will produce unusually warm overnight temperatures on Tuesday and Wednesday, making it difficult to sleep for people who do not have air conditioning. There will be an elevated risk of wildfires in the county’s backcountry, where the relative humidity will fall to the 15-to-20-percent range. The 2023-24 water year ended on Monday with San Diego International Airport recording 12.43 inches of rain, which was 2.64 inches above average. The water year — also known as the rainy season — extends from Oct. 1 to Sept. 30 of each year. Forecasters say the new rainy season could turn out to be drier than normal because a La Niña climate pattern is expected to settle in.