Hi @Sunny! Many factors can lead to burnt tips, but from what I read I think it's combination of heat and underwatering. With such high temperatures, make sure your medium is always wet. Good luck until the finish line! 👊
My first thought was a little light nutrient burn but it doesn't look like you're adding in any additional nutrients? The heat can burn the plants occasionally and i see you're up in the 90s and some of the leaves look slightly "tacoed" or curled up ward/inward. Maybe try a little extra shade or keeping the soil(sand) moist throughout the day or I've heard of people putting rocks at the base or mulch.✌️
Keep up the good fight
As Athos said, looks like nutrient burn. The plant will require significantly less nutrients towards the end of flowering. Journal looks great. Good luck and Happy Growing! 💪