Early evening is generally a good time for shortwave reception, the absorption in the lower ionosphere is mostly gone and the refracting/reflecting upper layers didn't fade out yet. Propagation of HF signals is mostly impacted by the conditions in the ionosphere at altitudes between 50 and 400 km along their path from transmitter to receiver (thousands of miles). Local weather is of little importance to HF reception, its impact in UHF and VHF bands is much bigger. (Shortwave is used for long-distance communication, MI is at about double distance from the airplane than the ground station.)
If your "random wire" is indoors, I recommend you to upgrade to an outdoors "long wire" antenna, a random length of wire, spanned between two supports (isolators!) tapped at one of the ends. If you have the space, a collection of tuned antennas would be great to have, but with wavelengths of most commonly used aviation frequencies lying between 30 and 100 meters that require some space.
