Jhansi sits on the Bundelkhand plateau at about 270 metres, and the climate is unforgiving in summer. From April through June the temperature regularly exceeds 45°C — not a good time to walk around fort ramparts in the sun. The monsoon arrives in July and brings relief, but also humidity and the occasional flooded road.
October to March is the window. November and December are the most comfortable: warm days, cool evenings, clear skies. January can be cold enough at night to need a jacket. The Orchha day trip is pleasant in this period too — the Betwa River is at a decent level from the monsoon runoff, and the monuments are not baking.
Jhansi hosts a significant Jhansi Mahotsav cultural festival in late February, usually around the anniversary of the 1857 revolt, with classical music, dance performances, and a light-and-sound show at the fort. Check local listings as dates shift year to year. The festival draws decent crowds, so book accommodation ahead if you plan to coincide.