Local seasonal weather variation is statistical noise, driven in part by ocean currents, but year to year, it's generally considered natural variation or statistical noise. Greenhouse gas seems to play a role in greater variation, so that's probably part of it (as are Ocean currents), but statistical noise/natural variation is almost certainly the bigger reason why a single season would be unusually hot or cold or wet or dry in a particular location.
It's kind of an astronomy question with two of your suggestions, but the astronomy part is mostly irrelevant.
The NASA June 2018 Temperature anomaly map shows more than 4 degrees C above normal in parts of Russia/maybe Northern China and parts of Antarctica. July 2018 isn't out yet but you can check that link in a couple weeks.
Precise reasons for local warm spells is a little complicated and more Earth Science than astronomy, Earth has warmed, as noted in the other answer about 0.75-1.00 degrees C, but that's global average. Over oceans the number is smaller and over land it's considerably larger than 1 degree and some regions are warming faster than others. The greenhouse effect may also play a role in greater temperature variation.
Increased solar activity
As noted in the other answer, solar activity is actually down this year, but the sun is very consistent. The variation in radiative energy during an active solar cycle and a quiet one is about 0.1%. Not enough to make a significant difference in local temperature on Earth.
Orbital Resonance. The Earth is closer to the Sun, due to
gravitational pull from other planet.
Orbital resonance has probably an even smaller effect year to year. It's true that if Earth is between the Sun and Jupiter, there will be a slight tidal effect that pulls Earth slightly further away from the sun, like a tidal bulge, The overall effect is pretty tiny on a year to year basis and I'm tempted to say virtually irrelevant.
Anybody know something about Orbital Resonance? The orbits are
affected by one another as they line up? Particularly the larger ones
like Jupiter, Neptune and Saturn?
This is a good astrology question, though I'm not sure it's specific enough to be a good question here. You're really asking about orbital perturbations from other planets. (orbital resonance is something else).
The Math behind orbital perturbation analysis gets pretty intense. Here's a question where it's answered somewhat on a single orbit. Over tens of thousands or hundreds of thousands of Earth orbits, Earth's eccentricity wobbles, mostly influenced by Jupiter and Saturn, and that eccentricity variation is thought to play a key role in the 100,000 year ice age cycle. But over single orbits the effect is tiny and not likely to affect seasonal weather.
There is, ofcourse, the butterfly flaps its wings theory, in which case, small changes like how much Jupiter moves Earth can have an effect in the sense that small input variations can lead to large changes down the line, but that's a local effect. Butterflies don't put more energy into the system, nor does every butterfly cause a hurricane, but they may be able to move them around, at least, that's what the non-repeating mathematical analysis tells us, so according to the butterfly effect theory, Jupiter might have an effect, but not a predictable or repeating one.
All that said, statistical noise is probably the real answer to your question. perhaps enhanced by greenhouse and affected by El Nino or La Nina, and for the most part, Jupiter and the Sun or not really factors, but it just might be that pesky butterfly in Africa. ;-)