BEIJING -- The Beijing meteorological observatory on Monday upgraded the alert for high temperatures to orange, the second-highest alert level, forecasting highs of 38 C.

The observatory has forecast that temperatures in most parts of Beijing's plain area will reach around 38 C between noon and 6 pm on Monday and Tuesday.

Weather authorities have advised the public to limit outdoor activities during periods of extreme heat and avoid prolonged exposure under the sun as the orange alert for high temperatures remains in effect.

The Chinese capital issued a yellow alert for high temperatures on Friday. As of 3:40 pm on Saturday, temperatures at an observatory in southern Beijing, widely seen as the city's official benchmark, had increased to 38.1 C, marking the hottest day of the year so far.

China has a three-tier warning system for high temperatures, with red representing the most severe warning, followed by orange and yellow.