Here’s a general rule-of-thumb breakdown of the main amateur radio bands from 160 m to 6 cm.

These are typical reliable performance characteristics under normal conditions (average solar activity, quiet geomagnetic field, no major storms, typical ham antennas and power levels). “Reliably” here means consistent, everyday QSOs you can count on most days/times—not rare DX openings, contests, or enhanced propagation like sporadic-E or tropospheric ducting.

Propagation on HF (160 m–10 m) depends heavily on the ionosphere (D-layer absorption by day, F-layer refraction at night). VHF/UHF (6 m and above) are mostly line-of-sight.

Grayline (twilight/terminator at sunrise or sunset) gives a temporary boost to lower HF bands because the D-layer weakens while the F-layer is still strong.

Distances are approximate and assume decent antennas (e.g., dipole or vertical).

Actual results vary with solar cycle, season, time of year, and your location.

HF Bands (160 m – 10 m)

160 m (1.8–2.0 MHz)

• Normal Day: Short-range only (groundwave ~50–200 miles). High D-layer absorption kills skywave. Mostly local/regional nets.
• Normal Night: Long-range skywave possible (continental to intercontinental DX, 1,000–several thousand miles), but noisy (especially summer static).
• Normal Grayline: Excellent—often the best time for true intercontinental DX. Signals can peak dramatically along the terminator.

80 m / 75 m (3.5–4.0 MHz)

• Normal Day: Local to regional (NVIS excellent for 100–400 miles coverage with low horizontal antennas).
• Normal Night: Good DX (worldwide possible in winter; 1,000+ miles common).
• Normal Grayline: Very strong enhancement for long-haul DX along the terminator.

60 m (5.3–5.4 MHz, channelized)

• Normal Day: Medium-range regional (a few hundred miles).
• Normal Night: Long-range DX similar to 80 m.
• Normal Grayline: Good boost, behaves like a slightly higher 80 m.

40 m (7.0–7.3 MHz)

• Normal Day: Local/regional (few hundred to ~1,000 miles).
• Normal Night: Excellent worldwide DX (even at solar minimum).
• Normal Grayline: Fantastic for DX—many operators’ best long-distance contacts happen here.

30 m (10.1–10.15 MHz, CW/digital only)

• Normal Day: Reliable regional to medium DX (~1,000–3,000 km / 600–1,900 miles).
• Normal Night: Longer DX (halfway around the world common).
• Normal Grayline: Nice enhancement; very consistent band overall with minimal day/night swing.

20 m (14.0–14.35 MHz)

• Normal Day: Excellent worldwide DX— the classic daytime DX band.
• Normal Night: Shorter range or may close; still usable for some paths.
• Normal Grayline: Minor benefit compared to higher bands.

17 m (18.068–18.168 MHz)

• Normal Day: Very good DX, similar to 20 m but slightly more solar-dependent.
• Normal Night: Often closes or very limited.
• Normal Grayline: Little special advantage.

15 m (21.0–21.45 MHz)

• Normal Day: Strong DX when open (best at solar maximum).
• Normal Night: Usually closes after sunset.
• Normal Grayline: Not much benefit.

12 m (24.89–24.99 MHz)

• Normal Day: Good DX during solar peaks; behaves like a mix of 15 m and 10 m.
• Normal Night: Generally closed.
• Normal Grayline: Minimal.

10 m (28.0–29.7 MHz)

• Normal Day: Excellent long-distance DX when the band is open (solar maximum or good conditions); otherwise regional.
• Normal Night: Usually closed.
• Normal Grayline: Not significant.

VHF/UHF Bands (6 m – 70 cm)

These are primarily line-of-sight (direct wave + some ground reflection). No real ionospheric skywave under normal conditions. Day/night/grayline differences are minimal—propagation is much more about antenna height, terrain, and occasional weather/atmospheric effects.

6 m (50–54 MHz)

• Normal Day / Normal Night: Mostly local/regional line-of-sight (50–100+ miles with good height; repeaters extend further). Can have more range than 2 m due to slightly better propagation.
• Normal Grayline: No special advantage. (Occasional sporadic-E DX openings can happen any time, but they’re not “normal/reliable” daily events.)

2 m (144–148 MHz)

• Normal Day / Normal Night: Local line-of-sight (typically 20–50 miles simplex handheld/mobile; 50–100+ miles with base antennas or repeaters).
• Normal Grayline: Irrelevant. Great for FM repeaters, SSB weak-signal, satellites, and local nets.

70 cm (420–450 MHz)

• Normal Day / Normal Night: Similar to 2 m but slightly shorter range due to higher frequency (more absorption by trees/buildings). Excellent for repeaters, ATV, and data modes in urban/suburban areas.
• Normal Grayline: Irrelevant. Line-of-sight only under normal conditions.

Microwave Bands (above 70 cm / 430 MHz)

These are strictly line-of-sight under normal conditions. Day/night/grayline differences are negligible—performance depends far more on antenna height, clear path, weather, and terrain. Higher frequencies have narrower beams, more path loss, and greater absorption by foliage, rain, or obstacles.

Common modes include FM repeaters, SSB/CW weak-signal, digital, ATV, and EME (moonbounce) with large dishes.

Tropospheric scatter can provide some beyond-line-of-sight range (hundreds of km) with high power and big antennas, but it’s not “reliable” daily for most operators.

33 cm (902–928 MHz)

• Normal Day / Normal Night: Local line-of-sight (typically shorter than 70 cm; 10–50+ miles depending on setup). More sensitive to obstacles. Used for weak-signal, repeaters, and data links.
• Normal Grayline: Irrelevant.

23 cm (1240–1300 MHz)

• Normal Day / Normal Night: Local line-of-sight with good direct paths (often 20–100+ miles with dishes or high-gain antennas). Popular for weak-signal CW/SSB and EME. Signals are more consistent than lower bands in some weak-signal work but still LOS-limited.
• Normal Grayline: Irrelevant.

13 cm (2300–2450 MHz)

• Normal Day / Normal Night: Shorter line-of-sight range than 23 cm due to higher loss. Requires clear paths and directional antennas (dishes common). Good for microwave experiments, data, and EME.
• Normal Grayline: Irrelevant.

9 cm (3300–3500 MHz)

• Normal Day / Normal Night: Even shorter reliable LOS range. Heavier absorption by rain/vegetation. Mainly for advanced microwave work, contests, and EME with parabolic dishes.
• Normal Grayline: Irrelevant.

6 cm / 5.7 GHz (5650–5925 MHz) and higher (e.g., 3 cm / 10 GHz, 1.25 cm / 24 GHz)

• Normal Day / Normal Night: Primarily short line-of-sight (miles to tens of miles with modest setups; longer with high power, large dishes, and elevated sites). Very narrow beamwidths. Rain can cause significant attenuation, though rain scatter sometimes enables DX. Tropospheric scatter is possible for beyond-LOS contacts with big antennas.
• Normal Grayline: Irrelevant. These bands reward clear weather, height, and precise antenna aiming.

Quick overall rule of thumb:

Low HF (160–40 m): Night and grayline for DX; daytime more local.

Mid/High HF (30–10 m): Daytime DX bands (solar-sensitive); 20 m is the most reliable all-around.

VHF (6 m–2 m): Local/regional anytime; repeaters make them very usable.

UHF/Microwave (70 cm and above): Strictly local line-of-sight. Range drops as frequency rises. Best with height, clear paths, and directional antennas. Great for high-speed data, ATV, and experimentation.