[scatters]

You can guess WARMS, which will either give you the answer (to input on the next try) or eliminate 4 of the possibilities, leaving only 2 to guess.

That's a best case of 2 additional guesses and worst case of 3 (expectation of 2 1/3) which is better than your strategy, which has a best case of 1, worst case 6, expectation 3 1/2.

[PebblesRox]

That's true for regular mode, but WARMS would be an invalid guess in hard mode once the last four letters have been established as IGHT.

[hvdijk]

The comment I replied to started with "You should give hard mode a try." In hard mode, WARMS is not a valid followup guess.