Teenagers are more likely to start smoking cigarettes or marijuana in June or July than in any other month, according to a new government study.

On an average day in June or July, more than 5,000 youths smoked cigarettes for the first time, while in other months, the daily average ranged from about 3,000 to 4,000 new users per day, according to the Substance Abuse and Mental Health Services Administration (SAMHSA). The study found that on an average day in June or July, more than 4,800 youths used marijuana for the first time, compared with 3,000 to 4,000 in other months, CBS News reports.

“More free time and less adult supervision can make the summertime an exciting time for many young people, but it can also increase the likelihood of exposure to the dangers of substance abuse,” SAMHSA Administrator Pamela Hyde said in a news release. “That is why it is critically important to take every opportunity we can throughout the year to talk to our young people about the real risks of substance abuse and effective measures for avoiding it, so they will be informed and capable of making the right decisions on their own.”

The study found first alcohol use increased to more than 11,000 teens a day in June and July and December. During the rest of the year, 5,000 to 8,000 teens start drinking on any average day.