Manava Dharmashastra 4.102

4.102

karṇaśrave 'nile rātrau divā pāṃsusamūhane
etau varṣāsv anadhyāyāv adhyāyajñāḥ pracakṣate //

Those who know the (rules of) recitation declare that in the rainy season the Veda-study must be stopped on these two (occasions), when the wind is audible at night, and when it whirls up the dust in the day-time.