Merino wool fabric is also suitable for the summer

Use a lighter 160g, 150g 100% merino or less in terms of weight or use a merino blend such as merino tencel blend. Tencel is a natural fibre and helps with moisture wicking. 

How does a merino wool fabric keep you cool , well it regulates the moisture balance and thus the body temperature. The fibres are hygroscopic, meaning they can bind moisture (in the form of water vapour).  The merino wool fibres wick moisture away from the body, absorbing it and releasing it to the outside. The moisture is temporarily stored in the fibre or between the fibres. The surface of the merino fabric remains dry. Merino wool fabric can absorb large amounts of moisture (up to a third of its own dry weight) without the fabric feeling clammy.

Warm ambient air causes the fabric to dry faster completing the wicking process.  

Some recommended fabrics are grey and pink stripes, Black onyx 100% merino, Limeade, Valencia orange, Harper black or Riverhead black and stripes merino tencel blend or a merino lycra tencel blend like Prussian blue. 

Eyelet fabrics also help with cooling as the tiny pinholes allow the heat to escape faster and also provide ventilation to allow cool air in. Try Whitby navy, Tango red, Plimco navy stripes or Linton turquoise.