New Delhi, June 24 : The India Meteorological Department (IMD) issued an orange alert for a few northern states, including the national capital, on Wednesday. The weather bureau also predicted that the monsoon would hit the region in 48 hours. "Conditions are favourable for advancement of monsoon into the remaining parts of Uttar Pradesh, entire western Himalayan region, Haryana, Chandigarh, Delhi, Punjab and Rajasthan during the next 48 hours," stated the IMD in its daily bulletin. The bureau has four colour-coded warnings as per the intensity of any weather system -- green, yellow, orange and the last one being red. Orange alert is given to prepare the authorities. The forecast during this warning is of heavy to very heavy rainfall. Parts of the capital city witnessed rainfall on Wednesday morning. The IMD has predicted "generally cloudy sky with moderate rain" for the next two days. The maximum and minimum temperature in Delhi will hover over 36 and 29 degree Celsius. The overall air quality index of the city is at the lower end of the satisfactory category. Heavy rainfall will also lash isolated places over Himachal Pradesh, Uttarakhand, Uttar Pradesh, East Rajasthan, Sub-Himalayan Jammu & Kashmir, Ladakh, Punjab, Haryana, Chandigarh, Delhi, West Rajasthan, Madhya Pradesh during the day. Monsoon is slated to arrive in the northern states a few days before the predicted date. It is being attributed to a cyclonic circulation, which moved towards southwest Uttar Pradesh on June 19 and June 20. Earlier on Wednesday, Ministry of Earth Science Secretary Madhavan Nair Rajeevan tweeted, "Monsoon activity to be shifted to foothills of Himalaya and North East region. Heavy rains and possible flooding over this area from June 25 to 28." The monsoon started with its timely onset over Kerala on June 1, marking the commencement of the four-month long rainfall season. Rajeevan said that heavy rains may again hit Kerala from June 26. "Elsewhere, activity will be subdued due strong westerlies over North-West India leading negative vorticity." The IMD had earlier said that the country will receive a normal monsoon between June to September. Monsoon rains are critical for farmers in India as the majority of the country's net-sown area does not have any form of irrigation. Farmers wait for the rains to begin for sowing of crops. /IANS