LUCKNOW, May 5 -- A sudden spell of unseasonal rain, thunderstorm and dense cloud cover plunged Lucknow and adjoining areas into darkness on Monday morning, catching residents off guard and sharply reducing visibility. Lucknow recorded 14.8 mm rainfall within an hour, while the maximum temperature dropped to 29 degrees Celsius, 10.4 notches below normal. The city also logged its lowest day temperature for May in the last four years. The minimum temperature, however, rose to 24 degrees Celsius. The weather office has forecast partly cloudy skies with thundery development and one or two spells of rain or thundershowers for Tuesday. The maximum and minimum temperatures are likely to hover around 31 degrees Celsius and 21 degrees Celsius, respectively. Across UP, 6.8 mm rainfall was recorded in the last 24 hours against the normal 0.5 mm. Among districts, Gunnaur in Sambhal received the highest 130 mm rainfall. Barabanki recorded the state's lowest day temperature, with the maximum settling at 26.5 degrees Celsius, 12.1 notches below normal. The district also received 53 mm rainfall. Rainfall accompanied by thunderstorms and hailstorms is likely to continue till Tuesday, with a gradual decline expected thereafter. Maximum temperatures may fall by another 4-6 degrees Celsius in the next 24 hours before rising again in the following days. An orange alert has been issued for over 20 districts, warning of thunderstorms, and winds of 50-60 kmph gusting up to 70 kmph....