Low frequency activity tends to fall off during the summer. Some of this is due to holidays and the need to spend more time working out of doors. But some is also due to a perception that propagation is poor in the summer months.
In fact, sky-wave propagation is still available but, because long distance contacts require darkness over most of the path, the number of hours of propagation in reduced. DF7FC is carrying out an exercise to demonstrate that he can be received in the US during every month of the year. He has succeeded so far, even in June.
Availability of medium distance sky-wave (eg UK-Moscow) is also reduced but contacts are still possible. Local contacts are often easier in the summer, with less multi-path fading.
A major summer issue is QRN - static from thunder storms - which can carry hundreds of kilometres (for current storm maps see: Americas , Europe/Africa or East Asia/Indonesia
for a continuously updated map of storms worldwide). There are some days without storms, so daily checking is worthwhile, and the static levels are usually greatly reduced in the mornings.
Choice of mode is important. For instance QRSS will outperform CW in high static conditions..
So why not dust off the LF transmitter and try out some summer activity? You may well be surprised.
