Blatter said FIFA officials and others "are starting now the consultations" on whether to move the World Cup from its traditional June-July slot to avoid summer heat in the Gulf, a decision that could drag into 2015.
"And when I say winter, I mean it can only be November and December," he told reporters in Abu Dhabi on Friday before the final of the Under-17 World Cup. "It can no way be January or February."
An IOC member, Blatter opposes the first two months of the year because it would clash with the 2022 Winter Olympics.
An April-May option has been proposed by Bayern Munich chairman Karl-Heinz Rummenigge, chairman of the European Club Association, which will be consulted by FIFA. When Qatar hosted the 1995 FIFA World Youth Championship for players under 20, the tournament was held in April.
January is favoured by Michel Platini, president of the Union of European Football Associations and potentially Blatter's rival in the next FIFA leadership election in 2015.
Blatter is scheduled to travel to Qatar for the latest round of discussions on whether to hold the tournament outside the Gulf summer, when temperatures can reach 122 degrees. Organizers in Qatar claim their plans for air-conditioned stadiums and other cooling measures could allow them to fulfil the hosting promises made when bidding.
Blatter will also discuss labour issues with the Emir in Qatar and is scheduled to hold a news conference on Saturday in Doha. Like other Gulf states, Qatar relies on migrant workers mostly from South Asia. Rights groups have long complained about abuses across the Gulf such as substandard living conditions and employers holding workers' passports.